A man accused of hiding in the hold of a plane in an attempt to steal £1.5m produced a forged passport as an alibi, the Old Bailey was told.
The box was dropped by cargo handlers at Heathrow Airport
Rawson Watson, 37, claimed he could not have been a stowaway found in a jet at Heathrow in January 2000, because he was in Africa at the time.
But the court was told stamps in his passport which showed he had been in Togo had been written over to change the dates.
Mr Watson, from Gillingham in Kent, denies attempting to steal the money and causing a fire hazard by damaging the British Airways jet.
'Constructed wooden boxes'
He is alleged to have hidden in a hole cut in the lining of the plane's cargo hold as it made a return trip to Madrid.
It is said he planned to smuggle himself and the money - £1.5m worth of Spanish pesetas which were loaded on board in Madrid - away in specially-constructed boxes.
The prosecution claims he got out of the hole during the flight to construct the wooden framed box in which he hid, along with a smaller cardboard box for the money.
But he was discovered when cargo handlers at Heathrow Airport dropped the box in which he was hiding and he fell out of it, the prosecution claimed.
Mr Watson, of Marlborough Road, Gillingham, told the court the man in the box could not have been him because he was backpacking in Africa at the time.
'Dates were changed'
Earlier this week his defence produced his passport, showing he had entered the Republic of Togo on 16 January, 2000 and not left the country until April.
But passport examiner Natasha Brunning told the jury on Friday that while the entry stamp was genuine, the exit visa had been tampered with.
She said examination under infra-red and ultra-violet lights had shown the figure 1 for the month of January had been changed to a 4 for April.
She said there were dots visible and shadows behind the writing and the passport would be treated as a forgery because of the tampering.
The court was also told the visa, written in French, stated it was only for seven days.
The trial continues.