A businessman who concealed cameras in his home and drugged women has pleaded guilty to a string of sexual offences, and police fear the full scale of his crimes may be “vast”.

Chao Xu, 33, pleaded guilty at a pre-trial hearing on Friday to 24 offences against six young women in London over three years, including rape, digital penetration, sexual assault, administering a substance with intent and voyeurism.

He was arrested in June and hidden cameras were found in multiple areas of his home, including inside an air freshener and in bathrooms. Police said searches of his phone found hundreds of intimate images and videos of women. His filming of his own offending was the key evidence that led to his guilty pleas.

Detectives have been able to identify three victims, with three others he was convicted of attacking still unidentified. Police believe his offending could go back years and that there could be many more victims. All of his victims are believed to be of Chinese heritage.

Xu owned a recruitment company and would use networking events at his home in Greenwich, south London, to select women to drug and then attack. After one event in June, a woman who had been raped four times went to police.

Police believe Xu would spike drinks and then when women felt unwell he would offer them a place to stay. Drugs recovered by police included substances usually used by vets to treat animals. Women said they had the effect of making them drowsy and incapacitated, during which time he attacked them.

The offences Xu admitted at Woolwich crown court were four counts of rape, eight counts of assault by penetration, four counts of sexual assault, four counts of voyeurism, two counts of administering a substance with intent, and two counts of operating equipment beneath the clothing of another without consent between February 2022 and June 2025. Two other alleged offences will lie on file.

The details of his offending have strong similarities to that of Zhenhao Zou, a Chinese student and serial rapist who drugged many of his victims and who is now serving a life sentence with a minimum term of 24 years.

Police are investigating whether there is any link between the two but so far none has been found.

Detectives are also talking to counterparts in China about whether they have any information on Xu, who came to Britain in 2013 to study at the University of Greenwich.

Police want any women who fear they may have been victims of Xu to contact them. The lead investigator, Det Ch Insp Lewis Sanderson, said: “Xu is a calculated prolific sex offender who has preyed on unsuspecting women using cowardly methods – administering drugs to rape, sexually assault and take intimate images without consent.

“Our investigation is ongoing and we continue to examine the large amount of evidence we have collected, which will help identify any further potential victim-survivors. We’re also asking anyone who has any information about Xu or believes they may have been a victim, to come forward – you will be listened to.”

Suzanne Crane, of the Crown Prosecution Service, said: “Xu is a serious danger to women, and the scale of his offending is such that without the brave testimony of victims who came forward after realising what had happened to them, [it] may well have continued undetected.”

Xu was remanded into custody until he is due to be sentenced on 14 November. The judge, Simon Stirling, told him: “You have pleaded guilty to a large number of offences for which the inevitable outcome is a lengthy custodial sentence.”