Police errors left him free to attack women

He was held for the attack on the 19-year-old in July 2007, nearly seven months before he was finally caught by a specialist serious crime squad. Astonishingly, police in Plumstead dropped the case against him despite the teenager's claims that she had been drugged and assaulted; CCTV images which showed him dropping her off and toxicology tests which indicated that she had taken sedative drugs.

Scotland Yard today announced that it had passed the matter to the Independent Police Complaints Commission and also revealed a major shake-up in the way the force investigates rape and sex attacks.

The student was picked up by Worboys in Covent Garden on 26 July after she had been on a night out with friends. Worboys offered her champagne, saying he had just won £3,000.

After a drink she began to feel drowsy but remembered Worboys stopping the cab, getting in the back and forcing her to take a pill. The student then blacked out and woke in her bed the following afternoon.

She had flashbacks about what had happened and went to the police. The matter was referred to a Project Sapphire team in Plumstead which specialises in dealing with sex assaults. The student was tested for date-rape drugs and, unusually, traces of a sedative were found. Police seized CCTV film outside her home which showed Worboys helping her out of his cab.

Police then went to his address but he was either not in or failed to answer the door. Later that day he surrendered himself at a police station.

Worboys denied any wrong-doing but, crucially, police failed to search his house where they could have found evidence of date-rape drugs.

Police also failed to pass on the complaint to the Crown Prosecution Service. Scotland Yard has refused to comment on why police dropped the case but privately sources say detectives simply did not believe that a black cab driver could have been involved in drugging and then sexually assaulting a woman in the back of his vehicle.

One of the officers involved in the initial Plumstead investigation, Detective Constable David Groom, gave evidence in court.

However, sources say the IPCC inquiry is expected to be more wide-ranging than about one individual and will focus on the roles of up to six officers involved in the case.

The inquiry will also examine why police failed to notice a series of assaults and complaints involving taxi drivers — all of them Worboys.

At the time of the July 2007 incident there had been nine attacks by a black- cab driver reported to police. However, the incidents ranged from kerb crawling to allegations of rape with differing suspect descriptions.

Worboys was only stopped when a link was established between three later cases and they were finally passed to the Homicide and Serious Crime Command. A week later, just as the investigating officer Detective Chief Inspector Tim Gratton-Kane was about to make a public appeal, an employee at a Haven rape centre told the team about the Plumstead case. Within hours officers had swooped on Worboys at his Rotherhithe home.

Today Scotland Yard revealed it had moved the responsibility for investigating rape and sex assaults from Territorial Policing to the Specialist Crime Directorate. Sapphire teams will still be based in boroughs but a new dedicated senior management team will be created under the overall authority of Commander Simon Foy who heads homicide inquiries.

Sapphire detectives will also be ring-fenced so they cannot be diverted by borough commanders to tackle other crimes.

The changes are based on a seven-month review of rape inquiries which was launched amid concern over the poor detection rate for sex offences.

In future, all allegations of sex attacks will be passed to the CPS. Police said the Worboys case was the first of its kind involving over-the-counter medication being used in sex attacks.