Carrie Johnson has warned that infamous black cab rapist John Worboys could have targeted up to 1,000 victims, as more women come forward in the wake of ITV's dramatized series Believe Me.Mrs Johnson, who helped bring the serial sex attacker to justice and also fought to keep him behind bars when he became eligible for parole, says she has since been contacted by women who believe they were assaulted by him.She told Good Morning Britain today: 'The truth is that his crimes span from, what we know, from 2000 up to when he was convicted in 2009.'And he was a cab driver for that duration, out potentially every night in his cab, so there could be up to 1,000, if not more than that. I just think the scale could be enormous.'Worboys, now 68, targeted lone women by luring them into his taxi late at night, before lying to them that he had won money and encouraging them to have a drink - which he had spiked - to celebrate.He then went on to rape many of his victims once they were incapacitated.Mrs Johnson, 38, previously told the Daily Mail how she was targeted by the sex predator, who persuaded her to drink a shot of spiked vodka after she got into his cab.After seeing media reports of a cab driver targeting women, she contacted police and went on to become a vital witness in the case against him. Carrie Johnson has warned that infamous black cab rapist John Worboys could have targeted up to 1,000 victims Mrs Johnson said more women have come forward since ITV's dramatisation of the case, Believe Me (pictured)The Parole Board last week said Worboys, who is serving a life sentence, 'continues to represent a high risk of committing further serious sexual offences against women' and denied his latest attempt to be released back onto the streets.He was first jailed in 2009 for 19 sexual offences linked to attacks on 12 victims between October 2006 and February 2008 in London, and given an indefinite sentence for public protection with a minimum term of eight years.In December 2017, a Parole Board panel decided he was ready for release, sparking a legal challenge by two of his victims that successfully got the decision overturned.Amid outrage over the battle, rules were then changed to allow some parole hearings to be held in public and permit better scrutiny of the processes used.Mrs Johnson, one of several women who spoke out to keep Worboys behind bars, said news he had been refused parole came as a 'huge relief' to many survivors.'I do not believe for one second, were he to be released, that he would not do something again,' she said. Mrs Johnson told Good Morning Britain that more people have come forward saying they believed they had been in his cab after watching ITV's dramatisation of the case.This 'might really help keep him behind bars for good', she added.The wife of former Prime Minister Boris Johnson said: 'I think there'll be women who, like me, were drugged, who might not realise they were drugged, who just thought, God, maybe that last drink didn't sit well with me, or, or now maybe they've seen what's happened and they think: 'Oh well, it's done.''I would urge them to come forward if they can.' Worboys, now 68, targeted lone women by luring them into his taxi late at night, before lying to them that he had won money and encouraging them to have a drink - which he had spiked - to celebrate. He is currently serving a life sentenceMrs Johnson previously wrote in the Daily Mail about her experience after getting into Worboys' vehicle in 2007. 'I was a 19-year-old university student when I got into the taxi of John Worboys – the man now known as the black cab rapist,' she said.'Nearly 20 years on, while much has changed, I fear the way the police deal with crimes such as sexual assault and rape is no better than it was then.'She recounted the night the cab driver spiked her drink after claiming he had won big at a casino.While she managed to pour one glass of champagne onto the floor, he later returned with a bottle of vodka, which she would discover had been spiked.After making it home, she said she 'never made it into my bed'.'Instead, I passed out in the bathroom, lying in the empty bathtub, fully clothed,' she said. She described how the room was left 'spinning' above her, with the effects of the drug so severe she 'wanted to die'.'If it had been a few minutes later I would have passed out,' she said today. 'I just remember telling my mum I wanted to die ever so bad.'Years later, allegations against Worboys emerged and a friend Mrs Johnson had confided in contacted her about the case.Mrs Johnson said she was able to identify him in a line-up and provided the police with a mobile phone number he had given her.The publicity around the case led further victims to come forward, and Worboys was charged with more crimes dating between 2000 and 2008, which he admitted.In 2019, he was handed two life sentences with a minimum term of six years.Worboys will be considered for parole again in around two years' time.