The brother of murdered private investigator Daniel Morgan has called on the Metropolitan Police to "come clean" after explosive new evidence suggested links between his killing and the death of Stephen Lawrence.
The Ellison report revealed Detective Sergeant John Davidson, who allegedly had a corrupt relationship with the gangster father of one of Lawrence's killers, was also connected to the investigation into 37-year-old Mr Morgan's 1987 killing.
It is thought he was set to blow the lid on police corruption.
Documents leaked to the Independent on Sunday this week suggested Mr Davidson was closely linked to one of the prime suspects in the murder, which remains unsolved despite five police probes, while Mark Ellison's report stated several officers who investigated the killing were suspected of corruption.
Speaking on the 27th anniversary of his brother's murder yesterday, Alistair Morgan said he believe a corrupt "firm within a firm" at the Metropolitan Police had been involved in covering up both murders.
He said: "We had always suspected that there could be crossovers but we'd never known anything specific.
"These are only allegations about Davidson but it clearly needs further investigation, because the Met, it seems, didn't give the right answers to the question.
"We want it all out in the open - everything. We won't stop until it is."
The 65-year-old, whose family has campaigned tirelessly for justice for nearly three decades, added he feared the Met's mass-shredding of documents on police corruption could jeopardise the work of an independent panel convened the review the investigations into his brother's death.
The top-secret Operation Othona, which ran from 1994 to 1998, uncovered widespread criminality within the Metropolitan Police but led to few prosecutions.
In 2003 the Met destroyed the intelligence gathered during the operation. The force has always denied that the Lawrence and Morgan murders were linked.
Mr Morgan said: "The revelation of the shredding of the Othona files, I find very worrying
"It makes me wonder whether papers will be missing from the independent panel that's looking into my brother's case, which is very worrying."
Home secretary Theresa May announced he establishment of the panel, constituted of independent experts, in May.
It will review how police corruption affected handling of Mr Morgan's murder investigation and treatment of his family.