Top civil servant Sir John Kerr again refused to answer questions when he appeared before the foreign affairs select committee.

Robin Cook gave me orders, says Sir John Kerr

He said he was acting on the orders of Mr Cook.

Earlier this month, Sir John, head of the diplomatic service at the Foreign Office, was threatened that he could be charged with contempt for repeatedly refusing to answer questions on the issue.

MPs on the committee ticked him off for his refusal amid allegations of a cover-up over which ministers knew what and when.

This time, Conservatives tried to re-open the Sierra Leone arms question during a session covering Foreign Office expenditure.

Sir John Stanley asked the diplomat what military advice Britain gave to the Sierra Leone government in exile before the arms shipment was agreed.

Stand-off in committee

Sir John Kerr told the MPs neither he nor his colleagues could not answer - on the orders of Mr Cook.

He told the MPs: "The Foreign Secretary has made clear that his answer is not no, his answer is not yet.

"I think you have to accept that given that officials give evidence before select committees on behalf of and on the instructions of their ministers, it is very difficult for us to answer questions which take us into an area which clearly will be covered by the Legg inquiry."

But the MP persisted, only to be told again there was a risk of prejudice to the official ongoing Legg Inquiry.

Another committee member, Labour's Ernie Ross, protested at the line of questioning and a stand-off developed.

Chairman Donald Anderson had no alternative but to go 'in camera' and journalists and members of the public were expelled from the session.