Beauty treatment firm Kommy Corp. said Monday that personal information on more than 37,000 customers who have used its Web site has been leaked.

The company, which operates Tokyo Beauty Center aesthetic salons, said someone hacked into their site's server and stole data on 37,810 people who had accessed the site between April 2000 and this month. The data include names, addresses, telephone numbers and e-mail addresses.

The company was alerted to the leak only when it was revealed on an Internet message board at around 1 a.m. Sunday. The site was shut down at 8:30 a.m.

The firm later posted an apology letter on its Web site and is working with police to find the party responsible for the leak, company officials said.