The British government is under increasing pressure to announce a public inquiry into the murder of Pat Finucane.
Sinn Féin and the rival nationalist SDLP both held protests on the 15th anniversary of the murder of the Belfast defence lawyer.
The British government has been in possession of retired Canadian judge Peter Cory's report into the murder and other controversial killings in which British Crown force collusion was alleged since October last year.
Speaking during a tour of Australia, Sinn Féin president Gerry Adams accused the British government of ``hiding'' behind the Cory report.
``Pat Finucane was murdered as a result of Britain's very deliberate policy of state-sanctioned murder,'' Mr Adams said.
``His family have refused to accept the lies and the barriers constructed by the British state in the years since his murder.
``The demand for a full public, judicial inquiry into the killing of Pat Finucane is undeniable. The British government hid behind the work of Judge Cory for three years in resisting this demand and now they are hiding behind the consequences of it.''
Mr Adams said Mr Blair could not continue to thwart a public inquiry into the solicitor's murder.
``He cannot continue to protect those within the British system who developed the policy of collusion and who are still actively engaged in cover-up and concealment.''
The Firinne group, made up of families who have had loved ones murdered as a result of alleged state collusion, held a protest outside PSNI headquarters yesterday.
Michael Power, whose son Michael was shot dead by the UFF in 1987 as a result of information supplied by British army agent Brian Nelson, said the families would continue their fight until they were given the truth about the murder of their loved ones.
``The Finucane family have waited 15 years and the British government is still trying to hide the truth from them,'' Mr Power said.
``Dozens of other families are suffering the same trauma as a result of the same British government intransigence. We demand the publication of the Cory report, the various Stevens reports and any other documents which can reveal why our loved ones were murdered by the state.''
He added: ``The review of the Good Friday Agreement is supposed to protect the rights of victims and their families.
``The time for the British government to tell the truth is now.''