Black cab rapist John Worboys has pleaded guilty to drugging four more women.
The 62-year-old, who now goes by the name John Derek Radford, targeted women who hailed his cab and drugged them in order to sexually assault them.
He was jailed in 2009 for sex assaults on 12 women and at an Old Bailey hearing on Thursday, pleaded guilty to a string of further offences relating to four more women.
Appearing via video link from Wakefield prison, Worboys, wearing spectacles and a light grey and green shirt, pleaded guilty to two counts of administering a stupefying or overpowering drug with intent to commit rape or indecent assault.
He also admitted two counts of administering a substance with intent to commit a sexual offence under the Sexual Offences Act.
The first victim was picked up in Worboys' taxi after leaving a bar.All the women made their allegations to police in early 2018, but the offences dated back to between 2000 and 2008 in London.
At his first trial at Croydon Crown Court in 2009, jurors were told Worboys picked up his victims in London's West End and plied them with champagne laced with sedatives on the pretext of celebrating a lottery or casino win.
One of his victims said: "I was completely in shock that he pleaded guilty after everything he has put his numerous victims through over the years.
"Whilst I can't help being cynical about his motives I am pleased that his victims have been saved the trauma of a court case."
Worboys, originally from Enfield, was convicted of 19 offences including one count of rape, five sexual assaults, one attempted assault and 12 drugging charges.
He was jailed for at least eight years but was told he would be held in custody as long as he was deemed a danger to the public.
Last year, the Parole Board ruled he should remain in prison citing his "sense of sexual entitlement" and a need to control women.
Police believe Worboys may have carried out more than 100 rapes and sexual assaults on women in London between 2002 and 2008.