MI6 death: Failings 'exacerbated' Williams' family's grief
The family of Gareth Williams, the spy found dead in a locked bag, has criticised MI6 for neglecting to make "basic enquiries" when he went missing.
A statement read by their solicitor also said they were "extremely disappointed" at MI6's "reluctance and failure" to release potential evidence.
They also hit out at the "total inadequacies" of the Metropolitan Police's counter-terror branch SO15.
MI6 has apologised for its week-long delay in reporting he was missing.
And Scotland Yard says it is now looking into "several new lines of inquiry" following an inconclusive inquest.
Gareth Williams, 31, worked as a code-breaker for security service MI6 before his body was discovered in a sports bag in the bath of his London flat in 2010.
Following a seven-day inquest into his death, coroner Fiona Wilcox said that Mr Williams was probably alive when he was placed in the bag.
She added that it was unlikely he had got into the bag by himself.
Delivering a narrative verdict, she said that he was probably unlawfully killed but there was not enough evidence for this to be conclusive.
Outside Westminster Coroner's Court, the Williams family's solicitor, Robyn Williams, read out a statement expressing their distress at the verdict, and criticising security services for failing to take the case more seriously.
He said: "To lose a son and a brother at any time is a tragedy. To lose a son and brother in such circumstances as have been outlined in the course of this inquest only compounds the tragedy.
"Our grief is exacerbated by the failure of his employers at MI6 to take even the most basic enquiries about his whereabouts and welfare which any reasonable employer would have taken.
"We are also extremely disappointed over the reluctance and failure of MI6 to make available relevant information."
Mr Williams thanked the coroner and police for their efforts, but called on Metropolitan Police Commissioner Bernard Hogan-Howe to "look into and review how this investigation will proceed in the light of the total inadequacies of the SO15 investigation into MI6 highlighted during this inquest".
MI6 chief John Sawyers apologised to Mr Williams' family, expressing the "deepest condolences" of MI6 and GCHQ for the death.
In a statement delivered by MI6 lawyer Andrew O'Connor, Sir John said the service should have acted more quickly when Mr Williams failed to turn up at work in August 2010.
Mr O'Connor said: "On behalf of the whole organisation, Sir John regrets this deeply and apologises unreservedly."
Responding to Wednesday's verdict, Det Ch Insp Jackie Sebire - who led the police inquiry - said she had "always been satisfied that a third party may have been involved" in Mr Williams' death.
"The inquest has raised several new lines of inquiry and the investigation will now refocus and actively pursue all the evidence heard and all the new lines of inquiry."
She added that the spy's "naked body was found in the most suspicious of circumstances" and urged those who knew him or had contact with him to "search their conscience and come forward with any information about what happened that night, on 16 August 2010".
"I would also ask anybody with any information to please come forward and speak to me, speak to my team and give Gareth's family some peace and allow them to just grieve and move on", she said.