Groupon Inc, the largest online daily deal company, said on Tuesday that the security of its Indian business SoSasta was breached.

Groupon said an information security expert told the company about the problem Friday morning Indian time, or Thursday night central U.S. time. The company didn't identify the expert.

Groupon said the breach involved all subscribers' passwords. It wasn't immediately known if email addresses were compromised.

Groupon said it fixed the problem immediately and has started telling SoSasta subscribers and advising them to change their passwords as soon as possible.

We will keep our Indian subscribers fully informed as we learn more, Groupon added in a statement. We are thoroughly reviewing our security procedures for SoSasta and are implementing measures designed to prevent this kind of issue from recurring.

Groupon stressed that the problem doesn't affect data from any other region, noting that SoSasta runs on its own platform and servers, and is not connected to Groupon sites in other countries.

We removed the information that had been unintentionally shared a Groupon spokesman told Reuters.

Chicago-based Groupon acquired SoSasta in January.

(Reporting by Alistair Barr, editing by Bernard Orr)