A former Scotland Yard detective has called for a new inquiry into the death of GCHQ codebreaker Gareth Williams in the wake of the Skripal poisoning case.

Colin Sutton, a onetime detective chief inspector with the force, was the most senior officer on the scene when he arrived at Williams' flat in Pimlico, London on August 23, 2010.

Williams, 31, from Anglesey in Wales, was found in a padlocked red holdall in his bath - with the Met concluding that it was most likely he had locked himself inside and been unable to get out.

Williams (right), 31, from Anglesey in Wales, was found in a padlocked red holdall in his bath - with the Met concluding that it was most likely he had locked himself inside and been unable to get out. Left: Sergei Skripal

During Mr Williams' inquest, a yoga expert failed to lock himself inside an identical bag without any outside assistance

Colin Sutton (pictured), a onetime detective chief inspector with the force, was the most senior officer on the scene when he arrived at Williams' flat in Pimlico, London on August 23, 2010

Speaking about the case in 2014, Sutton said he thought the flat (pictured with Williams' body being removed) was unusually warm when he arrived, claiming the heating was turned up to its maximum setting, possibly to assist with the decomposition of the spy's body

But Sutton has told The Sunday Times he suspects there may have been 'third-party involvement' in the death, which has previously been linked to Williams' work tracing Russian mafia cash.

He said: 'I think in light of the recent Russian activity in the UK it might be appropriate to take another look at the Williams case.'

The poisoning of former Russian spy Sergei Skripal and his daughter Yulia in Salisbury last month, blamed on Russia by the West, prompted Sutton's call.

He also once again raised questions about the behaviour of British intelligence agencies in the wake of Williams' death, accusing them of making the police investigation 'extremely difficult'.

Speaking about the case in 2014, Sutton said he thought the flat was unusually warm when he arrived, claiming the heating was turned up to its maximum setting, possibly to assist with the decomposition of the spy's body.

He said: 'If he had been poisoned, then the chemical compounds might have vanished by the time toxicology results were conducted.'

During an inquest into Williams' death, Coroner Fiona Wilcox ruled that the spy would not have been able to lock himself in the bag and was therefore likely to have died at somebody else's hands. Pictured: The spy cycling a year before his death

Sutton said: 'If he had been poisoned, then the chemical compounds might have vanished by the time toxicology results were conducted.' Pictured left: Williams at Holland Park Tube station on August 14, 2010. Right: His flat after his death

Sutton also said: 'I remain convinced the flat was tidied up after his death. that may have been to protect national security or it might have been something more sinister. If that's the case, then it could have been the perfect murder.'

The former detective explained that, after Williams' sister told GCHQ her brother was missing, police were not notified for five hours.

He said: 'Five hours. Why did it take so long? We know the property itself was owned by the spy agencies. I think it is reasonable to believe they would have had access to it.'

During an inquest into Williams' death, Coroner Fiona Wilcox ruled that the spy would not have been able to lock himself in the bag and was therefore likely to have died at somebody else's hands.