Tony Blair has expressed "profound regret" at events detailed in Police Ombudsman Nuala O'Loan's report into security force collusion with loyalist paramilitaries in Belfast during the 1990s.
The British prime minister's spokesman said: "This is a deeply disturbing report about events which were totally wrong and which should never have happened.
"The fact that they did is a matter for profound regret, and the prime minister shares that regret.
"But this is also a report about the past, and what is important now is that, under the new structures introduced along with the formation of the Police Service of Northern Ireland, these events could not happen now.
"What matters at this stage is that the whole community supports that process of transformation," the statement said.