The messaging service Durov founded with his brother in 2013 "was not created to be a platform for criminals", he told investigators through an interpreter, according to extracts from his questioning in December provided by the source.

"Its growing popularity, the overall increase in the number of our users, meant that the number using Telegram for criminal purposes also increased," added the 40-year-old, who possesses multiple passports including French.

"Every time we've been informed of illicit usage, we've tried to remove the users who have broken the law or the platform's rules," Durov said, numbering deleted accounts at between 15 and 20 million per month.

In 10 hours of questioning by the magistrates dealing with a sample of 15 criminal activities allegedly facilitated by Telegram's "ease of use", Durov said that he was "disgusted in a personal capacity".

He added that his company was "committing to improving our moderation processes", echoing a promise he made publicly in September to work more closely with authorities.