The Crown Prosecution Service (CPS) has defended its decision not to pursue scores of complaints against ‘black cab rapist’ John Worboys.

The comments come after it was announced on Thursday that the parole board had approved Worboys’ release following an oral hearing.

The move sparked an immediate backlash, with women’s rights campaigners and charity workers criticising the “shocking” decision to release the 60-year-old from custody.

Worboys used alcohol and drugs to incapacitate his victims between 2002 and 2008. 

The licensed London black cab driver told some women he had won money at a casino or lottery and offered them spiked champagne in an invitation to celebrate with him.

Questions have been raised about the decision by prosecutors not to pursue further allegations against the serial sex attacker.

More than 100 complainants came forward with accusations against Worboys but he was only convicted of 19.

The CPS said that of the 83 complainants initially referred to them by the Metropolitan Police Service during their investigation, just 14 passed the evidential test.

The cases of three more complainants referred to the CPS ahead of the trial passed the evidential test, but the CPS didn’t pursue these.

The CPS said “at that stage it had been decided that there were sufficient counts on the indictment to enable the judge to impose an appropriate sentence in the event of conviction”.

The CPS said its decision was taken in “full consultation” with the police.

Worboys was charged with 23 offences in April 2008, with the CPS believing “there was a realistic prospect of conviction”.

He was convicted of 19 of those offences following his trial in March 2009.

The Met Police informed the CPS that 19 more complainants had come forward following his conviction.

But the CPS said it would “be unlikely that it would be in the public interest” to prosecute Worboys in relation to allegations of sexual assault or administering a substance with intent because it would not impact sentencing.

The CPS said that former director of public prosecutions Sir Keir Starmer did not have “any involvement in the decision making” of the case. 

Scotland Yard said that there is currently no live investigation “as no new information has been received at this time”.

“Should any further information come to light it will be fully investigated,” police added. 

On Friday the chairman of the Parole Board “apologised unreservedly” for not informing victims of Worboys’ release.

Nick Hardwick said that he was “very surprised and shocked” to hear that victims had learnt about his release through media reports the previous day, and acknowledged it “would have been absolutely horrible for them”.

But he told the Today programme that it was the job of the Victim Contact Service to liaise with victims and the Parole Board believed they had done so in this case. 

The Ministry of Justice has since said that not all of Warboys victims chose to be updated about decisions relating to his imprisonment.