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.
Also Read
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 October 17.
She added that there had been no arrests and that enquiries by the Organised Crime Command were continuing.
The 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.
(Only the headline and picture of this report may have been reworked by the Business Standard staff; the rest of the content is auto-generated from a syndicated feed.)
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
)