One of the most studied murders of the Troubles, the killing of Pat Finucane involved several state agents and exposed their role within loyalist paramilitary groups.
The 39-year-old was gunned down by the UD/UFF in front of his wife and three children at their north Belfast home in February 1989.
Speaking at Westminster on Wednesday, South Belfast MP Claire Hanna said case is “mired in collusion”
In 1999, former UDA member and RUC Special Branch agent William Stobie was charged with murdering the solicitor.
The former quartermaster later admitted supplying the weapon used in the killing but denied murder.
Two years later the case collapsed after a key witness refused to give evidence.
Mr Stobie subsequently walked free from court but was later shot dead outside his home by loyalist gunmen.
In 2004, UDA member and state agent Ken Barrett confessed to driving the getaway car and was convicted for his part in the killing and released two years later under the Good Friday Agreement.
Another British army agent, Brian Nelson, has also been linked to the brutal murder.
Nelson, a UDA intelligence officer who provided information on murder targets, is also believed to have been involved with the importation of loyalist weapons in the late 1980s.
He passed a photograph of Mr Finucane to his killers before the murder.
Crucially, it has been reported that both Stobie and Nelson warned their handlers that Mr Finucane was to be killed but no action was taken.
Collusion in the murder of Mr Finucane has been accepted at the highest levels of the British establishment.
In 2003 an investigation by Sir John Stevens concluded there had been collusion in the killing.
Mr Stevens was not the only official figure to highlight the role of the state in Mr Finucane’s murder.
In 2011 a review was established and led by Sir Desmond de Silva.
He later concluded that he was left “in no doubt that agents if the state were involved in carrying out serious violations of human rights up to an including murder”.
After his findings were published in 2012, former British Prime Minister David Cameron made an unprecedented apology to the Finucane family at Westminster citing “shocking levels of state collusion” in the case.
