A senior minister has warned of an increased risk of sexual assault in nightclubs, clubs and bars following a suspected drug-fuelled rape in St John’s Wood in London.
Jemima Khan, a Labour MP, said more investigation was needed into the alleged attack, which took place in the early hours of Saturday 5 April.
The force said several of the 100 people who were in the club at the time were also treated for drug use.
St John’s Wood, a wealthy London borough, has two-thirds of the capital’s night-time economy.
Its nightlife attracts more than 9 million people a year.
Police said three people were in a consensual sexual relationship when a male victim and an unnamed man, who said he was only following the victim, got involved in a minor altercation.
He said a female member of his group was then raped at knifepoint, according to a police report seen by the BBC.
Ms Khan, who represents north-west London at Westminster, said on her Twitter account: “This is not the first reported incident in st john’s woods. What I now want are answers about the risk of sexual assault at places like this.
“There has been a worrying rise in the number of young women assaulted and a chill in the air which makes us worry that this will get even worse.
“I would also like to know if DJs/clubs are doing enough to tackle gang-sex. Please investigate.”
It is the second sexual assault reported at the club after a woman said she was raped by four males in a taxi on Saturday 2 January.
But officers have said those events are not linked.
A Metropolitan Police spokeswoman said police were leading a probe into the attack at the club but would not comment further on the role of other people attending the club.
She said: “No-one would want to look back and say, ‘why didn’t I protect young women?’, but we can’t simply walk away in an area, as we did in St John’s Wood, where we feel there was a gang of individuals there who might have possibly groomed and sexually assaulted young women.”
She added: “No-one wants to be the organisation that has to come in and assess the physical safety of people attending a venue.”
The Metropolitan Police’s sex crime command are investigating both events.
CCTV footage was circulated to private clubs – as well as local police – which set up patrols in the area as a precaution.
A number of clubs – including Mahiki – have publicly pledged their support to the victims.
Neither club would comment on the incident or say whether they employed private security.
The number of crimes committed where intoxication or drugs were suspected has been growing, according to Home Office data.
In 2014/15, 3,527 crimes were committed where there was an implied intent to provide or administer a drug to a person and 3,384 incidents where drugs were consumed and administered.
By Qeqed Dogar, BBC News