The evidence that undid a minister of the Crown

The evidence which damned Jonathan Aitken came from examination of airlines and car hire records. Mr Aitken, then defence procurement minister, had told Whitehall and later the High Court that he, his wife Lolicia, and their daughter Victoria were stopping off in Paris on their way to Switzerland where Victoria was to start at a new school.

They were to travel separately. Mrs Aitken and Victoria got to Paris before him and stayed at the flat of Said Ayas's sister. When Mr Aitken arrived he was told by Mr Ayas that mother and daughter had already gone to Switzerland. He stayed at the Paris Ritz before going to meet them.

He claimed the hotel bill was paid by Mrs Aitken when she returned to Paris from Geneva. The Guardian and World in Action maintained it was paid by an assistant of Prince Mohammed, and the real reason for Mr Aitken's visit to Paris was to discuss an arms sale. Acceptance of Prince Mohammed's hospitality would have meant Mr Aitken was in gross breach of guidelines on ministerial conduct.

The woman who settled the bill was a "brunette lady of European aspect", said the Paris Ritz's manager. On Thursday, Mrs Aitken was due to give evidence under oath that she was that woman. There had been much light- hearted banter in court over her hair. Mr Aitken had smilingly told the judge how his wife, who was now blonde, was in the habit of changing the colour.

According to this version, Mrs Aitken had returned to Paris and had a bath in Mr Aitken's room while he left the hotel. Later she paid part of the bill with cash given to her by Mr Aitken. There was shortfall accidentally covered by a nephew of Mr Ayas, who Mr Aitken later reimbursed. Mrs Aitken was going to be backed up in her evidence from the witness box by her mother and Victoria.

But then George Carman QC, counsel for the defence, produced British Airways documents showing tickets had been booked for Mrs Aitken and Victoria direct from London to Geneva and back, without a break in Paris. A sworn statement by Wendy Harris, who is employed by BA's Security and Investigation Services, said microfilm records revealed flight coupons for "Mrs L Aitken" and "Miss V Aitken" on the 8.30am flight from Heathrow to Geneva on 17 September. The coupons also showed return flights booked for Mrs Aitken from Geneva to Heathrow at 19.05pm on Monday 20 September, and for Miss Aitken at 12.05pm on 13 December. Ms Harris said: "It would not have been possible to retrieve flight coupons for a passenger unless they did travel on that flight."

In the case of Mrs Aitken the price was pounds 147 and, in Miss Aitken's case, pounds 242 - due to the interval between outward and return flights. Ms Harris concluded: "It follows from what I have said in this statement that the only way it would be possible for the plaintiff's wife and daughter to demonstrate that they did not in fact travel on the flights referred to would be if one of the following events occurred:

"By coincidence, two other ladies by the name of Mrs L Aitken and Miss V Aitken travelled on these flights;

"If there was a transfer of the tickets, for example if these ladies gave their tickets and passports to two other similar looking ladies who travelled under the names of Mrs and Miss Aitken, and this was not identified by passport control.

"In the absence of one of these eventualities, British Airways would interpret the information as indicating that Mrs L Aitken and Miss V Aitken travelled on the flights referred to in the documents."