Black cab rapist John Worboys has lost an application to appeal against two life sentences for attacking four women.
The 63-year-old, who is now known as John Radford, was jailed in 2009 for assaults on 12 women in London.
He was found guilty of four further offences in May 2019 after more victims came forward.
The Court of Appeal denied Worboys the right to challenge the life sentences handed out in December 2019.
Worboys, wearing a blue jumper and glasses, appeared in court via a video link from prison to observe the hearing.
His barrister, Joanne Cecil, argued it was wrong to impose a life sentence as he was already serving a sentence of imprisonment for public protection - which meant he could not be released until the Parole Board concluded he no longer posed a danger.
She also argued that the six-year minimum term, which formed part of the 2019 sentence, was "excessive".
But, giving the court's ruling, Lord Chief Justice Burnett rejected Worboys' appeal bid.
Police believe Worboys may have carried out more than 100 rapes and sexual assaults on women in London.
Worboys, from Enfield, north London, became known as the black cab rapist after attacking victims in his taxi.
In a number of instances, he pretended to be celebrating a win on the horses, or the lottery, as a pretext to giving his victims alcohol, which he had laced with drugs.
During his sentencing at the Old Bailey, the court heard he had told a psychologist his offending had been inspired by pornography, and he admitted plying a total of 90 women with alcohol, and drugging a quarter of them.
Worboys also said he had been "fantasising" about his crimes since 1986, and was motivated by "hostility towards women".
A probation report in August 2019 found: "He is potentially just as dangerous now as the point of the first sentence."