The UK's highest court will next week decide whether to grant a judicial review into the decision not to hold a public inquiry into the murder of Pat Finucane.
Mr Finucane (39), a high-profile solicitor, was shot dead by loyalist paramilitaries at his north Belfast home in 1989 as he sat down for dinner with his family.
State collusion in the murder was alleged and in 2004 a judge recommended that a public inquiry should be held into the slaying.
In 2011, however, the then-Prime Minister David Cameron decided not to establish a public inquiry, but instead ordered an independent review into to case by former UN war crimes prosecutor Sir Desmond de Silva QC.
Sir Desmond's review found "shocking" levels of collusion by the security forces in Mr Finucane's murder, but no "overarching state conspiracy" in his death.
Pat Finucane's widow, Geraldine, described the review as a "whitewash" and challenged the decision not to hold a public inquiry into her husband's murder.
Mrs Finucane argued the decision was incompatible with human rights legislation, the decision-making process was flawed and the previous commitment to hold a public inquiry was unlawfully frustrated.
The UK Supreme Court will hand down its judgment in the case on Wednesday, February 27.