It has emerged a third senior BAE Systems executive has been subpoenaed by US investigators as they probe allegations of bribery at the firm.
Head of Business Development Alan Garwood was served with legal documents while changing planes in Miami last month.
Garwood is also former head of the UK Ministry of Defence's Defence Export Sales Organisation.
Last month, CEO Mike Turner and Non-Executive Director Sir Nigel Rudd were detained and issued with subpoenas as they landed at Houston Airport.
They were kept for about half an hour and had their documents and personal electronic equipment examined.
The Department of Justice (DoJ) is probing the £43bn al-Yamamah arms deal under which Saudi Arabia bought aircraft and other defence equipment from Britain in 1985.
The US inquiry began after Britain ended its own Serious Fraud Office (SFO) investigation into the allegations in 2006 at the behest of the government.
Earlier this year, the High Court ruled the SFO had acted unlawfully in abandoning the case.
BAE says the DoJ had served "a number of additional subpoenas in the US on employees of BAE Systems plc and BAE Systems Inc as part of its ongoing investigation, which the company has previously announced".
"The company has been and continues to be in discussion with the DoJ concerning the subpoenas served in the course of its investigation."
By Elizabeth Clifford-Marsh