London Bridge Plastic Surgery (LBPS) said its IT experts and police found evidence of the breach.

A group claiming to be behind the breach said it had "terabytes" of data, the Daily Beast news site reported.

The Metropolitan Police is investigating the attack.

The alleged hackers, using the pseudonym The Dark Overlord, said they had obtained photos showing various body parts of clients, including genitals.

Some of these images have been sent to the Daily Beast.

The hackers also claimed that the data contained information on "royal families" and added that they planned to distribute the patient list and corresponding photos online.

"We are still working to establish exactly what data has been compromised," LBPS said in a statement.

"We are horrified that they have now targeted our patients."

A spokeswoman for the Metropolitan Police said it was notified of a suspected breach on 17 October.

She added that there had been no arrests and that enquiries by the Organised Crime Command were continuing.

LBPS is known to have high-profile clients, including model and TV presenter Katie Price, who recently used her Instagram account to thank the clinic for her facelift.

The Information Commissioner's Office said, "We are aware of this incident and are looking into the details.

"All organisations are required under data protection law to keep people's personal data safe and secure."

The Dark Overlord has claimed to be behind high-profile data breaches before, including one at US media firm Netflix earlier this year.

In April, 10 episodes of the new series of TV show Orange is the New Black were released online after Netflix refused to pay a ransom.