A co-pilot has been accused of forging documents to secure a captain’s role at a Lithuanian airline and later piloting hundreds of passengers on flights across Europe.

The fake pilot, whose name was not revealed, operated as a captain for the Lithuanian carrier Avion Express for an undisclosed duration. Reports indicate he did not possess the required credentials and had previously served only as a co-pilot with Garuda Indonesia, according to the German news outlet Aero Telegraph.

Avion Express, a “wet-lease” company that specializes in providing aircraft and full crews to other airlines, confirmed that it employed the pilot, who has since been removed.

“The company recently became aware of unverified information regarding his professional experience. An internal investigation was immediately launched and is currently ongoing,” a company spokesperson told the outlet.

The carrier also said that its hiring procedures line up with aviation regulations and assured that “safety and compliance” are the company’s “highest priorities.”

The man also piloted flights for other Western European airlines through Avion Express, including Eurowings, which is based in Germany.

Eurowings confirmed that it was “[taking] up the matter with our safety experts for a more detailed examination,” the outlet reported.

Avion Express was founded in 2005 and charters flights to Europe, Latin America and the Middle East. It is part of the larger Avia Solutions Group, a Lithuanian-owned holding group headquartered in Ireland.

Its fleet consists of 55 Airbus A320 family aircraft, which can seat up to 180 passengers, according to the Airbus Aircraft website.