Mike Turner, the BAE Systems chief executive, is likely to be forced to appear before an American grand jury if the defence company continues to drag its heels over a Department of Justice (DoJ) bribery investigation, a former head of the US Government department investigating BAE Systems has said.

Joshua Hochberg, the former chief of the department’s fraud section, has also said that if BAE is found to have used bribery to secure contracts, it would be compelled to repay billions of dollars in profits derived from those corrupt practices.

The DoJ is seeking to establish whether BAE bribed Saudi Arabian officials to win the so-called al-Yamamah arms contracts, which date back more than 20 years. Two years ago, Mr Turner estimated that BAE and its predecessor British Aerospace had earned £43 billion from the contracts.

Speaking to The Times, Mr Hochberg, who was responsible for investigating all breaches of the Foreign Corrupt Practices Act, explained that the recent heavy-handed behaviour of investigators indicated “a severe lack of cooperation by BAE”.

He added: “If they do not change their approach and the DoJ does not secure more active cooperation, it will subpoena records and witnesses and put him in front of a grand jury.”

If an individual is forced to appear before a grand jury, they are required to give evidence under oath and are not allowed a lawyer.

Mr Hochberg, now a partner at McKenna Long and Aldridge, a Washington corporate law firm, noted that if BAE is found to have bribed officials, it will probably demand the return of net profits earned from the al-Yamamah deals, which were signed under the Thatcher government.

Last week, it emerged that both Mr Turner and Sir Nigel Rudd, a nonexecutive director of the defence group, were separately detained as they travelled through Houston, Texas and Newark, New Jersey airports. Both were asked to hand over electronic equipment and were issued with new subpoenas.

Both Mr Hochberg and Alexandra Wrage, president of Trace International, a nonprofit group that specialises in antibribery cases, have argued that the tough stance of the DoJ is highly unusual. They said that companies that are being investigated by the DoJ tend to develop a dialogue with the Government department and cooperate by supplying the documentation requested, making subpoenas and detentions unnecessary.

Should the DoJ find that BAE Systems bribed officials to secure arms contracts, it would impose fines, claw back net profits derived from corrupt practices and, crucially, ban the company from bidding for contracts from the United States Government. More than half of BAE’s business is derived from America.

Separately, the DoJ can compel BAE Systems to provide documents and witness statements so that it can pursue individuals that it suspects of having been involved in criminal activity.

A spokesman for BAE declined to comment yesterday on Mr Hochberg’s remarks but pointed to its statement published on Monday that read: “The company has been and continues to be in discussion with the DoJ concerning the subpoenas served in the course of its investigation.”

BAE has denied any wrongdoing.

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