The partner of murdered young mother Rachel Nickell has revealed the heartbreaking moment he discovered she had died and their two-year-old son was in hospital.

Miss Nickell was stabbed 49 times on Wimbledon Common in London while walking her dog Molly with her son Alex on July 15, 1992 in a crime that shocked the nation.

The 23-year-old was also sexually assaulted by the attacker before he fled and Alex was found by a passer-by next to his mother, repeatedly saying: 'Wake up, Mummy.'

Now, André Hanscombe has told a new Netflix documentary out tomorrow about how he fell to the ground after police informed him of an 'accident' involving his partner.

In a new clip issued to the Daily Mail today, an emotional André says: 'A man's voice answered the phone and my blood ran cold. I just knew immediately that something was seriously wrong. He said: "I'm a policeman". So I said: "Where's Rachel?".

'And he said: "There's been an accident". I said: "Is she dead?" He said: "I can't tell you that". I said: "You just did". I asked: "Where's Alex?". He said: "Alex is safe, he's at hospital". He said: "André, stay where you are, we'll send a police car to you".

'The moment I put the phone down I collapsed to the floor, broke down. Every belief I had about the firmness of reality disappeared. I was in a state which you can only describe as bordering on the edge of insanity.'

The clip from 'The Murder of Rachel Nickell' also features moving home videos of Alex, André and Miss Nickell playing together in a park with the family dog.

After the murder, André moved with Alex to rural France to start a new life and to avoid him being found – given the boy was the only person to have witnessed his mother's killing and was therefore in danger while the killer was still at large.

Some 32 men were questioned and the original suspect Colin Stagg - a local man who walked his dog on the common - spent 13 months in custody, enduring more than a decade of speculation that he was the killer.

Stagg was freed by an Old Bailey judge in 1994 who criticised police for using a 'honeytrap' undercover policewoman to try to make him confess to the murder.

Mr Justice Ognall, who halted the trial, called it a 'blatant attempt to incriminate a suspect by positive and deceptive conduct of the grossest kind'.

The case was reopened by Scotland Yard in 2002 using advanced DNA forensic techniques that had developed in the intervening years and identified convicted murderer Robert Napper as a suspect.

Napper pleaded guilty to manslaughter on the grounds of diminished responsibility in 2008 and was ordered to be detained indefinitely at Broadmoor Hospital.

At the same time, Stagg was awarded £706,000 compensation from the Home Office for the bungled probe, but revealed in 2017 that he had spent all the cash.

A separate clip from the Netflix documentary first revealed by the Mail in April showed Alex chatting with André about how the knife-wielding murderer had killed his mother in front of him.

The clip shows Alex – now aged three - and André sat at a table, with the boy dressed in a Thunderbirds outfit as he says: 'Dadda, can you help me draw Mummy on this piece of paper?' 

André then calmly says to his son: 'Alex, look at me. When you saw the bad man, was he in front of me like I am, or was he on this side, or was he on that side?'

Alex says that the man was 'in front of me'. André asks: 'Did Mummy see him?' Alex says: 'I don't think she did' and then confirms that he saw the man first.

Alex says the man had a bag. André asks: 'Did he open it, or was it already open?' Alex says: 'He opened it.' André asks: 'And what did he get out?' Alex says: 'A knife.'

André then asks his son: 'What did he do to you?' Alex is heard saying: 'He knocked me over.' Alex draws a picture on paper, and André asks: 'What's he sticking in her?'

Alex says: 'A knife, there's his knife.' When André asks him whether 'did you see it', Alex replies: 'Yeah, I saw the knife.' The boy adds: 'I saw it, yeah I saw it all.'

The documentary from Bafta-nominated director Lucy Bowden will examine the police investigation with archive footage, first-hand accounts and forensic insights.

Also coming out on Netflix tomorrow is a new drama about the case called 'The Witness', which will follow investigations into the murder from Alex's point of view after he was the only witness to her death.

The series, which is spread across three hour-long episodes, will see André and Alex navigate the lengthy and bungled police investigation in the aftermath of the tragedy.

André decided to move with Alex to a farmhouse in France for their safety as the killer remained at large, then moved to Spain when their address was discovered.

The drama features Jahsaiah Williams and Max Fincham as Alex, Jordan Bolger as André, Eleanor Williams as Miss Nickell and Kerry Godliman as June.

Other actors include James Bradshaw as DCI Tony Nash, James Dryden as DC Paul Miller, Kevin Eldon as DCI Mick Wickerson and Neil Maskell as DI Keith Pedder.

André and Alex spoke to the Daily Mail's Kathryn Knight for their first major newspaper interview together ahead of the broadcast, in an article published on Saturday which can be read by clicking here.

'The Murder of Rachel Nickell' begins streaming on Netflix tomorrow