SOFIA (Reuters) - Bulgarian police said on Monday they had broken an international sex-trafficking ring and arrested a Greek man believed to have run the operation.

The women from Moldova, Ukraine and Uzbekistan were sent as sex workers to Greece via neighbouring Bulgaria using fake Bulgarian identity documents, police said in a statement.

Police said they had charged the Greek man with trafficking.

Surveys by Bulgarian non-governmental organisations say that sex-trafficking brings in about 1.8 billion euros (1.4 billion pounds) a year to the gangs behind it, making it the European Union newcomer's most profitable criminal activity.

(Reporting by Anna Mudeva; Editing by Bate Felix)