A champion kickboxer who failed to turn up to give evidence after witnessing a "grisly" murder at a Bexley gym has been spared jail for contempt of court.

Luke "Skywalker" Whelan, 28, who sparred with Hollywood actor Idris Elba, went into "fright mode" after seeing the killing of new father George Barker at Double K gym in November 2016.

Suspected drug wholesaler Charles Riddington, 37, fled the country after stabbing 24-year-old Mr Barker 17 times but was brought back to face justice at the Old Bailey.

Ahead of the trial last August, Whelan received repeated contact from the victim's family which triggered a perceived "fear for his safety", the court heard.

Shortly before he was expected at court, Whelan left his bank cards and phone at his mother's house and was dropped off by his girlfriend at King's Cross station.

Despite a warrant for his arrest, Whelan disappeared for three weeks, only resurfacing after the trial had finished.

In his absence, extracts of his witness statement were read to the jury in which he described Riddington producing a lock knife and aiming targeted stabs at Mr Barker's face.

Disputing Whelan's account, Riddington had claimed he acted in self-defence after Mr Barker produced the weapon.

Riddington, from Orpington, was jailed for at least 19 years after being found guilty of murder but acquitted of possession of the knife.

The court heard that if he had been found guilty of having the murder weapon, the sentencing starting point would have been 25 years.

In December, Whelan, a lightweight kickboxer ranked 5th in the world, accepted being in contempt of court before Judge Nigel Lickley.

As he appeared to be sentenced on Thursday, the court heard he was suffering from post-traumatic stress disorder (PTSD).

The court was shown the "grisly" aftermath of the stabbing, with Mr Barker lying in a pool of blood and Mr Whelan looking shocked and tearful as he was led away by police.

On why he failed to give evidence, his barrister Sam Trefgarne said: "It was clear he wanted to move forward with his life and any reminder of the murder brought back distressing images."

His post-traumatic stress disorder also made him "hyper vigilant to any threat", he said.

The lawyer added: "It was not something planned long in advance when he had been plotting to not give evidence for some time. It was something, when faced with the impending prospect of giving evidence, he took the decision to leave and not give evidence."

Professor James Hacker Hughes, a clinical psychologist, told the court: "By witnessing the murder of Mr Barker, Mr Whelan absolutely witnessed an event where someone's life was not only in danger but was ended.

"He definitely had post-traumatic stress disorder at the time. One of the features is avoidance, doing anything not to think about what he saw that day."

Asked if being a kickboxer made his likely response to any threat different, he said: "I know having asked Mr Whelan about this and I know having seen the video that the court has just seen, that Mr Whelan was not able to intervene in this murder - he was told in quite clear terms by some of the people who came in the gym to stay exactly where he was."

He was not able to go into "fight mode", and instead went into "fright mode", Prof Hacker Hughes added: "He could not run away. He was trapped.

"There were perceived threats from the family of the victim. There was a possibility of having to return to court and see the evidence we have just looked at."

Judge Lickley sentenced Whelan to three months in jail suspended for 12 months, saying it was "unacceptable" for witnesses of serious crimes to refuse to give evidence and it would have been "so much better" had he told people or witness support of his issues.