A PhD student who charmed women so he could drug, video and attack them has been convicted of raping 10 women in London and China, with police fearing he may have 50 more victims.

Zhenhao Zou, 28, was convicted by a jury at Inner London crown court on Wednesday, after more than 18 hours of deliberations.

One senior police source said the extent of his violence against women could be the worst seen in Britain, with detectives still examining mountains of evidence that may show he carried out many more attacks.

Zou was convicted of raping three women in London and seven in China, between 2019 and 2024. He filmed most of his rapes, and the videos provided key evidence leading to him being convicted and facing years in jail.

Most of his victims, who in the videos are unconscious or stupefied because of the drugs he gave them, are as yet unidentified. He ignored their pleas to stop his attacks as they lost consciousness after being drugged, videos played in court showed.

Detectives have recovered more videos and believe they show he committed 50 further attacks. They believe half of the rapes took place in Britain – almost certainly in London – with his victims being young women of Chinese heritage.

Zou told the jury he was a user of extreme pornography who was aroused most by watching videos of sex with unconscious women, as well as by rape role play.

In all, Zou was convicted of eleven rapes, on 10 women, as well as one count of false imprisonment.

He was also found guilty of 10 counts of possessing extreme pornography, three counts of voyeurism, and three counts of committing an offence, namely having butanediol, to commit rape. In all he was found guilty of 28 counts.

He was acquitted of seven counts, including of having MDMA, ketamine and alprazolam so that he could commit rape, and two counts of possessing an extreme pornographic image.

Zou is now the subject of what is believed to be the biggest rape investigation in Britain. The Metropolitan police appealed for anyone who fears they may have been a victim of the seemingly charming well-off student to contact them.

In court, Zou, who was studying engineering at University College London, bragged of having “five new sexual partners every month”.

The Met commander Kevin Southworth said Zou was “predatory and cowardly” and one of the worst offenders the police had investigated in recent times. The effect of the date rape drugs could mean victims may not know Zou attacked them.

Southworth said: “This man may well turn out to be one of the most prolific sexual offenders we have ever seen in this country.”

About 50 videos believed to contain more attacks have been examined, as well as 1,660 hours of footage in Mandarin, and 9m social media messages. “Some women may not know they were victims,” said Southworth.

Victims gave harrowing accounts of their ordeal.

The prosecutor, Catherine Farrelly KC, said Zou appeared respectable and a gentleman, but the reality was different. “He was a wolf in sheep’s clothing and every woman’s nightmare,” she said.

“He was a man who was sexually excited by having sex with a sleeping woman … and sexually excited by the idea of rape. He is a serial rapist, he is a predator. He would use drink or drugs to incapacitate women.”

During one video, a woman said: “I really don’t want … I beg you, don’t do this …” and Zou replied: “Don’t push me, it’s pointless … The sound insulation here is very good.”

His tactic was to invite women to his home in Woburn Place, central London, or a flat in south London, for drinks or to study. He met them socially or via dating apps.

One victim went to Zou’s home for drinks, which were drugged, and later felt tired. Zou had sex with her. She told police: “I can’t fight back, I have no strength,” and was raped while unconscious, the court heard. Video of the incident shot by a camera on a bedside table confirmed her account.

The woman’s speech was slurred, and she complained of feeling unwell and wanting to go home, later telling Zou not to restrain her. She screamed and tried to get up from the bed on several occasions, with the defendant pushing her back down.

The first woman went to the Met on 18 November 2023. Zou was not arrested, and two days later flew to China. He was arrested on his return to the UK in January 2024.

The jury was told that searches of Zou’s London home had found drugs including MDMA, butanediol, ketamine and alprazolam.

Police also found a trove of designer clothing with some still having the tags on, as well as a box believed to contain “souvenirs” of his victims.

Zou gave evidence during the trial across five days, changing his evidence as he went along.

In a police interview he claimed he had one date rape drug for use as a moisturiser for dry skin, but then changed his story before the jury to claim he used it to get high when he went out clubbing. In fact, it was used to carry out his attacks.

Zou said he was “in the habit” of filming himself having sex. He first came to Britain to study in 2017 at Queen’s University Belfast. Two years later he started studying at UCL.

The jury was given a majority direction for four remaining counts about whether drugs Zou is alleged to have had were used to help him rape his victims. But after further deliberations, he was found not guilty.

He will be sentenced on 19 June.