Failing to track down a white Fiat Uno that may have been in the tunnel on the night Princess Diana was killed in a car crash is a lasting "frustration" of the French inquiry into her death, investigators say.

Diana was 36 when she was killed in a car crash in Paris on August 31, 1997, and her death has continued to attract conspiracy theories over the decades.

Detectives from the 1997 French Brigade Criminelle have told a Channel 4 documentary, Investigating Diana: Death In Paris, the driver could have helped explain the movements of the black Mercedes she was travelling in.

"The whole of the world has struggled to accept that the Princess of Wales died in a mundane accident," said Martine Monteil, head of the Brigade Criminelle.

"I have frustration about the Fiat Uno because I like a well-finished business.

"For sure, it's out there. Unfortunately we don't have it.

"But you know the driver of the Fiat Uno, he's not the real culprit.

"He's driving along quietly and then a Mercedes arrives at high speed and bumps into him. The responsibility remains with the Mercedes."

The black Mercedes Diana and her partner Dodi Al Fayed were travelling in was being pursued by the paparazzi after they left the Ritz Hotel in Paris.

It crashed in the Pont de l'Alma tunnel.

Fayed, 41, son of Harrods owner Mohamed Al Fayed, and driver Henri Paul died.

Bodyguard Trevor Rees-Jones survived.

A couple at the scene saw a white Fiat Uno coming out of the tunnel with a driver who was focused on his mirrors, the investigators said.

The couple described a brown-skinned man with short hair and a dog wearing a muzzle being in the car.

Traces of white paint were found on the black car and its tail light was broken.

Fabrice Cuvillier, of the Brigade Criminelle, says the Fiat Uno exists, telling the program: "It's not a hallucination. It's not something we threw out to create a diversion. It exists.

"We did not find this Fiat.

"But it would be dishonest of me to look you in the eye and say 'we didn't let the Fiat Uno slip through'.

"I don't think so, but I'm not 100 per cent sure."

Eric Gigou, of the Brigade Criminelle, said "we did everything we could to understand what happened" and more than 1000 people were interviewed in the investigation by the French authorities.

"In my mind the only door that remains open is the testimony of the driver of the Fiat Uno," he told the documentary.

Diana's death became the subject of many conspiracy theories, from claims by Dodi's father that the couple were murdered in a plot hatched by MI6 on the orders of the Duke of Edinburgh, to suggestions Diana was pregnant.

Other theories centred on the lack of CCTV footage from the tunnel and the mysterious white Fiat Uno, which is said to have come into contact with the Mercedes, but which has never been traced.

Ten years after the crash, an inquest found the princess was unlawfully killed because driver Henri Paul was drunk and driving too fast, the car was being chased by photographers and Diana and Dodi might have survived had they been wearing seatbelts.

© PAA 2022

Alex de Minaur has continued his hot American summer to steam into the US Open second round in New York.

The Australian No.1 carved out a 7-5 6-2 6-3 victory over Serbian Filip Krajinovic to live up to his 18th seeding status.

The straight-sets victory atoned for a first-round exit last year after previously producing his two best grand slam results at Flushing Meadows.

He was a quarter-finalist in 2020 and reached the last 16 the year before.

Relishing the faster conditions, de Minaur swept past Krajinovic in less than two hours to book a potential rematch against his Wimbledon conqueror Cristian Garin.

"Happy to get a win against a tough opponent. I thought I did what I needed to do out there and very happy to be in the second round," de Minaur said.

"Nice, hot, quick, swirly conditions. It wasn't, as I would call it, beautiful tennis but I did exactly what I needed to do.

"At times I expect perfect tennis out of myself. Reality of the sport is that it's not always going to come, so it's about adapting and kind of just being able to accept mistakes.

"That's for me the biggest thing. Just move on and keep fighting and try to win every point out there and staying in the moment.

"Over five sets, it's definitely tough to get through me."

Garin broke de Minaur's heart at the All England Club last month, fighting back from two sets down and saving a match point to deny the Australian a place in the quarter-finals.

The Chilean was up against Czech Jiri Lehecka in his opener in New York later on day one.

"Good thing is I'm in the second round and they're out there on court right now," de Minaur said.

"I'll take whoever I have to play. It will be just another match. Look, of course if I play Garin, then hopefully I can get some revenge."

De Minaur arrived at the season's final major full of confidence after snaring his sixth career title four weeks ago in Atlanta, and also claiming two top-25 scalps in Montreal.

"The one thing I would say coming into this match I probably haven't had before is the confidence in myself that I'm very tough to beat over five sets if I'm there competing every single point," the world No.20 said.

"Especially in hot conditions, I was ready to play for as long as I needed to. That gave me a bit of confidence."

De Minaur's first projected seeded opponent is Spain's world No.15 and two-time US Open semi-finalist Pablo Carreno Busta in round three.

De Minaur is among seven Australians scheduled for action on Monday, with Nick Kyrgios taking on doubles partner Thanasi Kokkinakis in the feature men's night match (about 11am Tuesday AEST).

Ajla Tomljanovic, Daria Saville and Jordan Thompson also play.

But John Millman has already crashed out with a five-set loss to American wildcard Emilio Nava.

© AAP 2022

Alex de Minaur is eyeing sweet revenge after continuing his hot American summer to steam into the US Open second round in New York.

The Australian No.1 carved out a 7-5 6-2 6-3 victory over Serbian Filip Krajinovic in less than two hours to live up to his No.18 seeding status.

The straight-sets victory atoned for a first-round exit last year after previously producing his two best grand slam results at Flushing Meadows.

He was a quarter-finalist in 2020 and reached the last 16 the year before.

Relishing the faster conditions, de Minaur swept past Krajinovic with minimal fuss to book a spicy rematch against his Wimbledon tormentor Cristian Garin.

"Happy to get a win against a tough opponent. I thought I did what I needed to do out there and very happy to be in the second round," de Minaur said.

"Nice, hot, quick, swirly conditions. It wasn't, as I would call it, beautiful tennis but I did exactly what I needed to do.

"At times I expect perfect tennis out of myself. Reality of the sport is that it's not always going to come, so it's about adapting and kind of just being able to accept mistakes.

"That's for me the biggest thing. Just move on and keep fighting and try to win every point out there and staying in the moment.

"Over five sets, it's definitely tough to get through me."

Garin broke de Minaur's heart at the All England Club last month, fighting back from two sets down and saving a match point to deny the Australian a place in the quarter-finals.

The Chilean downed Czech Jiri Lehecka in four sets in his opener on Monday to confirm another showdown with de Minaur.

"Hopefully I can get some revenge," de Minaur said.

The world No.20 arrived at the season's final major full of confidence after snaring his sixth career title four weeks ago in Atlanta, and claiming two more top-25 scalps in Montreal.

"The one thing I would say coming into this match I probably haven't had before is the confidence in myself that I'm very tough to beat over five sets if I'm there competing every single point," de Minaur said.

"Especially in hot conditions, I was ready to play for as long as I needed to. That gave me a bit of confidence."

De Minaur's first projected seeded opponent is Spain's world No.15 and two-time US Open semi-finalist Pablo Carreno Busta in round three.

© AAP 2022

Chris Dawson will either be found guilty of murder or acquitted as a highly anticipated judgment is delivered over the 40-year-old disappearance of his wife Lynette.

Within hours, NSW Supreme Court Justice Ian Harrison will hand down his verdict after seven weeks considering witness testimony and submissions in Dawson's two-month long murder trial.

Dawson, 74, is accused of murdering his wife and disposing of her body in January 1982 so he could have an unfettered relationship with his then teenage babysitter, known only as JC, and retain assets such as the family home in Bayview, Sydney.

Aged 33, Mrs Dawson vanished without a trace in early 1982 leaving behind her two daughters. Her body has never been found.

According to evidence given at trial, JC moved into the Dawson home within days of the disappearance. She eventually married her former high school teacher in 1984, with the pair separating in 1990.

Inquests in 2001 and 2003 recommended that a "known person" be charged with the murder of Mrs Dawson. No charges were laid, however, until Dawson was arrested at his Gold Coast home in December 2018.

The former Newtown Jets rugby league player pleaded not guilty to murder and has maintained his wife simply left home and cut contact to start a new life because of his affair.

Crown prosecutors are relying on claims Dawson was violent and abusive towards his partner before she vanished.

JC has also alleged she went with him to hire a "hitman" to get rid of his wife, but that he changed his mind at the time.

Dawson's legal team has pointed to a myriad of witnesses who claim they saw Mrs Dawson alive and well after January 1982.

They have also blamed The Teacher's Pet podcast, released by The Australian regarding Mrs Dawson's disappearance, for contaminating evidence and infecting how witnesses viewed the former high school teacher.

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© AAP 2022