Telegram CEO Pavel Durov was arrested on Saturday and is in custody as part of a cybercrime investigation, the Paris prosecutor said in a statement Monday.

The investigation involves crimes involving illegal transactions, child pornography, fraud and failure to provide information to authorities, the prosecutor said.

A case was opened last month over child pornography, drug sales, fraud and other criminal activity on the platform. The app’s creator, Pavel Durov, was arrested near Paris over the weekend.

Edition The New York Times reported that Durov’s detention was related to an investigation launched on July 8 “against an unnamed individual” on a range of potential charges, including complicity in the distribution of child pornography and drug trafficking, money laundering and failure to cooperate with law enforcement.

The investigation is being carried out by cybercrime and anti-fraud specialists, the prosecutor explained.

“It was within this procedural framework that Pavel Durov was questioned by investigators,” the statement notes.

It is not yet clear whether any of the listed charges will be brought, the NYT adds.

In France, complex criminal cases are handled by special magistrates with broad investigative powers. They can conduct a formal investigation, bringing charges if there are sufficient grounds to do so.

However, magistrates may later drop charges if they find the evidence insufficient to proceed to trial, and the case may be delayed.

The news is being updated