Serjeant at Arms
has told MPs she "deeply regrets her error of judgement" in the events leading to the arrest of Damian Green MP in November 2008.
Jill Pay was giving evidence on 7 December 2009 to the specially convened Committee on Issue of Privilege, set up following the search of Mr Green's offices.
She claimed she had been pressurised into "going down a particular route", by not being told by the Metropolitan Police that she could request a warrant before allowing the search of Mr Green's offices to go ahead.
Opening her evidence, she admitted that she should not have accepted the duty of confidentiality that she claimed had been placed on her by representatives of the Met.
However she denied that she had ever deliberately withhold information from the Speaker.
Ms Pay has been criticised in earlier evidence sessions by the former Speaker of the Commons Lord Martin and the Clerk of the Commons Malcolm Jack for not alerting them to the forthcoming search.
Lord Martin told the committee in November 2009 that Ms Pay had been "tricked or bamboozled" by the Metropolitan Police into not telling him about the forthcoming search, a claim denied by the Met.
However she claimed she could not recall those words being used.
Earlier in the session, the former clerk of the Commons, Sir William McKay told the committee that he felt permission to grant a warrant or allow a search of an MP's offices should be granted by the Speaker.
Damian Green was arrest as part of an investigation into alleged leaks from the Home Office, although all charges were eventually dropped.