Where is Peter Falconio's body? Key questions in British backpacker mystery

The pair were driving through the Northern Territory on a part of the Stuart Highway when they were flagged down by another vehicle.

Falconio got out of the car to help the other driver identify a potential problem in his vehicle.

While Lees took the driving seat to help try the engine, she heard a loud noise, something she believed to be a gun shot.

The other driver then approached her in the car, pointed a gun in her face before attempting to kidnap her.

Lees successfully managed to escape and eventually flagged down a truck a couple of hours later to help her make an emergency call.

However, when the police arrived at the scene, Falconio's body was missing, only a pool of blood in the place Lees said the incident took place. The pair's vehicle was found 80 metres away.

Following a 16-month investigation, the police located the vehicle they believed to belong to the mysterious driver. Combined with CCTV footage, they arrested Bradley John Murdoch.

Murdoch was sentenced to life in prison in 2005. Falconio's body has never been found.

In Murder in the Outback former defence lawyer Andrew Fraser reveals new information and the main questions he has with the case in the hope he can overturn Murdoch's conviction.

What was the red car and the "jelly man"?

When Joanne Lees was picked up by Vince Millar she was taken by them to a rest stop and cleaned up a bit while they waited for the police.

Fraser shares footage of him interviewing Vince Millar in the documentary casting light on what else happened that night. Andrew Fraser says Vince's report was never fully investigated as he points out the truck driver says he saw something before Joanne appeared in the road.

He talks about headlights "doing circles and lights going on and off". He also talks about a red car he sees on the side of the road that had "two blokes" inside and a man sat between them - the third man was "like jelly". Before Vince could help the men drive off, but now he says the "jelly man" could have been Peter Falconio. Who was in the red car?

Why wasn't there more DNA?

The case against Murdoch started with the small bit of DNA on Joanne Lees' t-shirt, but she describes her attacker touching her - and never mentions them wearing gloves.

Experts in the documentary admit that Murdoch didn't have to be at the murder scene for the DNA to get on Joanne's clothes. Andrew Fraser tries another theory.

The pair stopped at the Red Rooster restaurant in Alice Springs before the attack. DNA expert Brian McDonald says it would have been possible if Murdoch had visited too for his DNA to transfer to her t-shirt if they sat in the same chair.

The lack of DNA was also an issue. If Joanne had been wrestled to the ground or even pushed like she said then DNA from her attacker would be expected to be on her clothes more than just the speck on her t-shirt.

If the attacker didn't wear gloves it makes it even more strange there wasn't more DNA.

Where was Peter's blood?

Andrew Fraser also flags up that there wasn't much blood at the scene if Peter was shot.

Joanne describes a loud bang which she says was a gun shot killing Peter.

The police found three areas where blood was spilled on the road, but there was no sign of a body being dragged, no blood trails or additional pools of blood as you'd expect.

Joanne has never said what happened to Peter after the gunshot as she was being wrestled to the ground, but she has guessed he was dragged away.

In the documentary, Professor Barry Boetcher, a blood expert, raises questions over this explaining that if blood was there a blue luminescence would be seen by police.

"If a body had been shot and then dragged somewhere you would expect a blood trail. There was no blood trail in this case. Further than this, there was no blood splatter found at the scene."

He goes so far to say that the jury would not find a guilty verdict in this case today.

Why were there only Joanne's footprints?

If Joanne and Peter were pulled out the car, Joanne alive and Peter shot, then why were there only Joanne's footprints found by police. The one set of prints were found in the dust.

Joanne also mentions a dog but there were no dog prints either.

What about the other witness accounts?

There are a few points in Joanne Lees' story that raise questions, one being she said she never stopped at the Alleron roadhouse on the day of the murder. Owner Greg Dick claims he saw the couple and he saw Joanne talking to a man who matched the description of her attacker.

Who was the other man?

Trucker Phil Creek also describes a man matching the same description but at a pub near the scene. He claims the man told him he was camping nearby on the night, and he talked about getting out fast and possibly shooting his dog as he could get another. Joanne describes a dog as part of her statement.

Police eliminated the man from their enquiries.

Where is Peter Falconio's body?

While Peter's body has never been found there's never been a shortage of theories as to where he could be buried, whether that is down a well or long gone as part of an animal attack.

John Daulby, the Northern Territory Police Assistant Commissioner, who led the case, said: "Where is Peter's body? The only person who knows that is Murdoch. Will he stand up and say where it is? I hope so."

The fact there isn't a body has also led to speculation that the backpacker is alive.

Is Peter alive?

Witnesses have claimed to have seen Peter Falconio after the murder took place.

Robert Brown and Melissa Kendall claim to have seen Peter in Bourke, a remote town in New South Wales 2,000 km from where the attack is said to have taken place.

“I’m 200 percent sure it was Peter Falconio,” said Brown in the documentary. “I will undergo any lie detector test, anything anybody wants me to. I was a metre away from him.”

Robert walked the cameras through his sighting of Peter Falconio adding that when he walked out he saw the vehicle the men will filling up tucked behind the wall in the street, which he found odd. The vehicle he saw that day he claims was the same as the artist's impression in the newspaper article about Peter.

All four parts of Murder in the Outback is on Channel 4 and All4. If you're looking for more to watch, check out our TV Guide.