Civil servants should not resign over the foreign prisoners fiasco which cost Charles Clarke his job, the Cabinet secretary has said.
Charles Clarke was sacked over the controversy
Sir Gus O'Donnell told MPs it was not clear civil servants were "directly accountable" enough for the debacle.
Mr Clarke was sacked as home secretary after it emerged 1,023 foreign prisoners were released without being considered for deportation.
Mistakes had been made and lessons would be learned, said Sir Gus.
The UK's top civil servant was questioned about the controversy by the Commons public administration committee.
He said it was sometimes difficult to divide policy, which was the responsibility of ministers, from "delivery".
"If you ask Charles Clarke, he was clear he takes responsibility for the department and all it does. Certainly from the civil servants' side mistakes were made and we need to learn from that," he said.
Asked if civil servants should have resigned over the controversy, Sir Gus replied: "I'm not clear that there was sufficient direct accountability for that to be appropriate.
"This would have been assessed by line managers along the way and people will be looking at what lessons to learn and what staff changes are necessary."
A "wide range of officials" were responsible for "a number of jobs", he added.