David Cameron has angered the family of a solicitor shot dead in Belfast in 1989 by rejecting their demand for an independent public inquiry.
The Prime Minister apologised to relatives of Pat Finucane yesterday, saying he accepted there had been "state collusion" in his murder.
But family representatives, led by his widow, Geraldine, walked out of a Downing Street meeting with the Prime Minister. She said she had been insulted by Mr Cameron's offer to review the case and felt so angry she could hardly speak.
One of Belfast's best-known solicitors, Mr Finucane was killed by three loyalist gunmen in front of his family in an attack that immediately led to accusations of collusion by the intelligence services.
The allegations were supported by separate reports by the former Metropolitan Police chief Lord Stevens and a former Canadian judge Peter Cory.
A spokeswoman for Mr Cameron said: "He accepted these conclusions and on behalf of the Government he apologised to the family.
"He expressed his profound sympathy for the family and said it was clear from Stevens and Cory that state collusion had taken place in Mr Finucane's murder."
A review of the case is to be carried out by a QC. Mrs Finucane said after the meeting: "I am so angry and so insulted by being brought to Downing Street today to hear what the Prime Minister had on offer.
"He is offering a review. He wants a QC to read the papers in my husband's case and that is how he expects to reach the truth. All of us are very upset and very disappointed."