Investigating Diana: Death in Paris: when is Channel 4 documentary on Princess Diana’s death out, and trailer

It has been 25 years since Princess Diana, the ‘People’s Princess’ died in tragic car crash in Paris, which also cliamed the lives of her partner Dodi Fayed and driver Henri Paul.

Investigations by police forces on both sides of the Channel found the deaths to have been the result of a terrible accident but, in the weeks, months and years since the incident, conspiracy theorists have suggested more sinister causes of death.

Channel 4 four-part documentary Investigatin Diana: Death of a Princess follows the police investigations into the Princess of Wales’ death.

The series also explores some of the more shocking conspiracy theories that have proliferated over the years, some of which suggested that Diana was murdered.

The documentary features exclusive interviews with experts who have never publicly discussed the investigation before, and aims to separate fact from speculation.

What is Investigating Diana about?

Investigating Diana follows the two major investigations in Princess Diana’s death - one by the French Brigade Criminelle in 1997 immediately after her death, and the Metropolitan Police’s investigation which was launched in 2004.

Detectives from both investigations feature in the documentary and speak openly about their work.

Conspiracy theories surrounding the circumstances of Diana’s death began to circulate within days of the event, and investigators had to remain objective in their analysis of the facts.

The documentary explores the problems that plagued each investigation, including unreliable witnesses, a media circus, rumour mills, and a huge amount of public pressure to find satisfactory answers.

Diana’s death also sparked a lot of online discourse, even though the internet was still in its infancy, and Investigating Diana uncovers some of the theories put forward on online chat rooms.

Investigating Diana looks at how these phenomena created a perfect storm which threatened to derail any investigation as the very nature of objective truth was brought into question.

Henry Singer, executive producer for Sandpaper Films said: “This was a really important series to make - not only because we hope it will lay to rest the conspiracy theories that continue to obscure the truth of what happened in the Alma tunnel that night - but because the story is a window into the world today, where conspiracy theories are no longer reside in the dark corners of the internet but have gone mainstream and are actually pushed by people in positions of real power”.

Who is featured on the documentary?

Lord Stevens, aged 79, was Metropolitan Police Commissioner at the time of the 2004 investigation, called Operation Paget, which lasted three years.

He features on the documentary to explain his role in the investigation - he appeared on This Morning and said: “Well it’s transparency, [we want] people to understand what we did and why we did it and what the conclusions were.

"I just hope, at the end of the day, people understand we did a really good job and worked very hard under immense pressures.”

Senior investigating officer, David Douglas, who worked with Stevens on Operation Paget, also features in the documentary.

From the French investigation, Martine Monteil, who was head of the Crime Squad at the time, and Lieutenant Eric Gigou, who led the Brigade Criminelle investigation, give their side of the story.

Also featured are paparazzi who were in Paris at the time, eyewitnesses, and first responders.

When is Investigating Diana on TV?

The first episode of the four-part series will air on Channel 4 at 9pm on Sunday 21 August, and will be followed by The Diana Interview: The Truth Behind the Scandal, a documentary about Diana’s infamous interview with Martin Bashir.

The next episode will air at 9pm on Monday 22 August, and the final two parts will be broadcast at 9pm on Sunday 28 and Monday 29 August.

Episodes will be available to watch on All 4 shortly after they are first broadcast.

Is there a trailer?

Yes there is, and you can watch it right here: