(Bloomberg) -- The US Justice Department has joined a group of international agencies investigating how thousands of bogus engine parts backed by forged documents ended up in planes around the world, according to people familiar with the matter, as fallout grows over a scandal that has spread across the commercial aviation industry.

The DOJ has sought information from at least one airline that removed unapproved parts linked to AOG Technics Ltd., according to one of the people, who asked not to be identified because the information isn’t public.

The Justice Department’s involvement marks the first indication of scrutiny by law enforcement into the issue, which was reported by Bloomberg News in August. The probe is in early stages and may not result in charges. At least one non-US authority has shared information with other enforcement agencies, according to another person, indicating a coordinated effort to pursue the case across national boundaries.

Read More: Airlines Are Racing to Hunt Down the Fake Parts in Their Fleets

The Civil Aviation Authority, the European Union Aviation Safety Agency, and the US Federal Aviation Administration have all warned airlines of suspect parts sold through AOG. Each regulator has been looking into the matter, although it hasn’t been clear whether law enforcement agencies were involved.

AOG, an obscure London-based company, has been accused by aviation regulators of falsifying paperwork and supplying unauthorized components for CFM56 turbines, the world’s most widely used jet engine, powering workhorse aircraft from Boeing Co. and Airbus SE.

A lawyer previously used by AOG Technics said they no longer act for the company or its founder, Jose Alejandro Zamora Yrala. The Justice Department declined to comment. Zamora didn’t immediately respond to a phone call seeking comment.

The FAA, which is responsible for airline safety in the US, said it refers all suspected unapproved parts cases to federal law enforcement agencies. It declined to comment on AOG Technics specifically. EASA, its counterpart in the EU, had no immediate comment.

The UK CAA said it’s supporting the FAA and EASA in looking into the supply of unapproved parts. 

Airline Fleets

The scandal has reverberated around the industry as the number of airlines finding unapproved parts on their aircraft has grown. The incidents have affected carriers from Portugal to the US and as far as Australia, underscoring the global nature of the problem and the industry’s effort to contain it. Delta Air Lines Inc., American Airlines Group Inc., Southwest Airlines Co. and United Airlines Holdings Inc. all found parts with suspect documents on their planes. 

CFM International Inc., an engine-making joint venture of General Electric Co. and France’s Safran SA, said last month it had found 145 engines in the global fleet that were fitted with the parts linked to AOG. More than half of the affected engines have been removed from service, a CFM spokesman said then. 

The findings came after CFM completed an “exhaustive” review of records supplied by AOG under a court order obtained by the CFM partners in September. Roughly 180 forged records have been found, with bogus parts from the supplier fitted into 145 of the 22,600 CFM56 engines in service. 

--With assistance from Ryan Beene, Upmanyu Trivedi, Albertina Torsoli and Julie Johnsson.

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