The chairman of the Parole Board will be summoned before MPs to explain how the decision to free serial sex attacker John Worboys was reached.
Professor Nick Hardwick has apologised “unreservedly” over the failure to inform Worboys’ victims of his imminent release, something he will also be questioned about by the House of Commons Justice Committee.
He said he fully accepts there was a problem with the parole system, and that it was believed the victims had been informed before the decision was issued.
Chairman of the committee, Conservative MP Bob Neill, said: “What has happened here is very disturbing. It is vital that the public has confidence in Parole Board decisions.”
Mr Neill added: “We will also want to ask about how the parole system can be made much more transparent, something Nick Hardwick himself has rightly called for.
“In my view, it is ridiculous that the current rules prevent the board making public the reasons for their decisions. Professor Hardwick has called for MPs to back ‘opening the process up’ and we will give him the opportunity to make precisely that case.”
Speaking on BBC Radio 4’s Today programme on Friday, Prof Hardwick said he is still trying to establish precisely what happened and does not want to “blame anybody yet”.
He said it was not the Parole Board’s responsibility to inform victims, and added: “Whoever’s fault it was, I fully accept this was a problem with (the) parole system.
“I’m chair of the Parole Board, this would have been absolutely horrible for those two women concerned, and I apologise for it unreservedly.”
London cabbie Worboys, a former stripper and adult film star, was jailed indefinitely in 2009, with a minimum term of eight years, for drugging and sexually assaulting women passengers.
In a statement, Prof Hardwick said the Parole Board has a “statutory duty” under its rules which “prevents disclosure of proceedings”, and revealed he will be launching a public consultation on how decision-making is shared with the public.
Lawyer Harriet Wistrich said two victims she has represented had not been informed of Worboys’ imminent release or of his Parole Board hearing.
She told the Press Association they are both “shocked and horrified by this news”.
It is understood that all those who were signed up to the Victim Contact Scheme were informed as soon as the Parole Board decision was made.
A Ministry of Justice spokesman described Worboys’ crimes as “truly horrendous” and extended their thoughts to the victims for the “pain and suffering they have endured”.
He said it is “right” that victims decide whether and how they want to be kept updated, and that some in the cases chose not to be.
“Others chose to be informed by phone or email and were contacted immediately; others chose to be informed by letters which were sent straight away, but of course take longer,” he added.
“Our priority is to support victims and it is right that we respect their decisions about how they are contacted.”
Worboys, who became known as the “black cab rapist”, was found guilty of 19 charges of drugging and sexually assaulting 12 women passengers, in one case raping a woman.
But police said in 2010 that his alleged victims numbered 102 after more people came forward following his trial and conviction.
The allegations were investigated but no further action was taken on the advice of the Crown Prosecution Service (CPS), police said.