An airline passenger caught with a gun and ammunition in his luggage said his father's servants had packed the bags and he did not know they were there.

Security officers at Gatwick discovered the dismantled Smith and Wesson .457 - missed by staff at Manchester airport on an earlier flight to Pakistan - during a routine scan.

At first, Mohammed Haider, a US citizen of Pakistani origin, was detained under prevention of terrorism legislation but any terror links were eliminated.

He appeared before Lewes Crown Court yesterday to admit illegally possessing a weapon and was jailed for four months. The 39-year-old is expected to be released within a few days because of time spent on remand since his arrest on December 9.

Richard Barton, prosecuting, said Haider was travelling with his wife and three young daughters on a flight back from the Middle East when he arrived at Gatwick to board another to the USA.

The gun and two magazines of ammunition were found during a check of the family's 11 suitcases.

Mr Barton said when Haider was first questioned he said he did not know what was in the bag because his father's servants had packed his luggage. The court heard he later admitted buying the gun from a former police officer for his own protection while running a filling station in America.

When the family moved to Pakistan last year he had been unable to sell the weapon and decided to take it with him.

Barney Branston, defending, said Haider was a man of good character.

He said his client had taken the "stupid" decision to retain the gun rather than dispose of it in Texas and then went to extraordinary lengths to conceal it because he feared it would fall into the wrong hands if his luggage was broken into on the journey.