A man has been arrested after a London firm was accused of supplying fake aircraft parts used by airlines across the world.
The Serious Fraud Office (SFO) said its investigators carried out a dawn raid at a site in London used by AOG Technics and arrested one person who remains in custody.
The firm mostly sold to overseas companies that install airline parts but some UK airlines were also impacted, the SFO said in a statement.
It added that “some planes have been grounded in the UK and the US”.
AOG Technics has been accused of supplying falsely documented parts for use in the world's most-sold passenger jet engine, the CFM56.
CFM56 engines power the previous generation of Boeing 737s and about half the previous generation of Airbus A320s.
Earlier this year, the UK's Civil Aviation Authority (CAA) and its counterparts in the EU and the US issued alerts warning businesses about unapproved parts sold by AOG Technics.
Affected airlines include Tui, Ryanair, American Airlines, Delta Air Lines, United Airlines, Southwest Airlines, TAP and Virgin Australia Airlines.
SFO director Nick Ephgrave said: “This investigation deals with very serious allegations of fraud involving the supply of aircraft parts, the consequences of which are potentially far-reaching.
“The SFO is best placed to take this investigation forward vigorously and we are determined to establish the facts as swiftly as possible.”
The agency said it is working closely with the CAA and other regulators as part of the inquiry.
The suspected forgery came to light after reports made by a Portuguese maintenance company in June.