It was meant to be a quiet afternoon working at his computer.

But when a smouldering metal object came crashing down on Greg Smith's conservatory roof from the sky above, it left him feeling lucky to be alive.

At first, Greg, 61, of Claudius Gardens in Chandler's Ford, thought the "tremendous cracking sound" was kids throwing stones at his house.

But when he took a closer look, he found that a large metal washer had fallen with such speed that it had pierced two layers of tough reinforced plastic just above his head.

He said: "I was sitting in my conservatory when there was a loud bang on the roof. It was like a loud crack and I thought what the hell was that'.

"I dashed outside but could not see anybody. Then I took another look and thought it must have come from a long way up."

"I don't think anybody could have thrown it up into the sky high enough for it to have caused that much damage and make such a noise when it hit.

"After it happened I started to feel a little bit shaky. It could have been a lot worse - if I had been outside hanging out the washing and it had fallen on my head I could have been killed."

Luckily, the object stopped short of crashing through the third layer of roof plastic.

Investigate Mr Smith, believing the washer had fallen from an aircraft, immediately contacted the Civil Aviation Authority to investigate. They informed him that items frequently fell from aeroplanes and helicopters and agreed to examine the mystery object.

"My guess is that it came from the undercarriage of a plane," said Mr Smith. "It must have come down at a tremendous speed. And it looked like it could have been hot at the time it hit because part of it had melted."

Now he has been left with a hefty repair bill and the prospect of a higher insurance premium.

He said: "I have just paid £1,500 to have the roof replaced and the company said it is going to cost the same to replace it. I don't think there will be any compensation, but at least the CAA are going to look to try to find out who owned the plane."