An Israeli who blamed "poor memory" for having a loaded gun in his hand luggage has been cleared of any wrongdoing.
Benjamin Lehman, 48, went through several checks at Tel Aviv's Ben Gurion Airport and through customs at Heathrow without the pistol being detected.
It was only discovered when he tried to board a flight to the USA a few days later on 17 June last year.
But on Thursday, a jury at Isleworth Crown Court found him not guilty of two counts of "having a dangerous article".
Mr Lehman was travelling to a wedding in America and had stopped off to spend time with his parents in Hendon, north London.
It was when he returned to Heathrow to continue his journey that the pistol showed up as a "dark shadow" on an X-ray scanner screen. His bag was searched and the gun was found.
The court heard the $1,000 (£550), 9mm Steyr M9 pistol, which contained 10 rounds of ammunition, was found in one of the pockets of his rucksack.
Mr Lehman blamed a combination of tiredness, the rush to pack, the pressure of family life, a lengthy town council meeting and a poor memory, subsequently diagnosed as
attention deficiency disorder, on him forgetting about the gun.
He argued this amounted to a "reasonable excuse" and therefore a defence in law.
Giving evidence during the three-day trial the computer company manager said his ordeal had triggered a huge inquiry in Tel Aviv and checks had since been doubled.
The father of six, who explained that he carried a weapon "like other people carry handkerchiefs", said after the verdict: "I have had six months of absolute hell and pressure... I am just so relieved it is all over.
"However, it was worse for my family. It traumatised my children."