An elderly man has warned others to beware after being conned out of his life savings by bogus builders.

The 81-year-old victim, who lives in Heston , says he handed over £5,800 to fraudsters for work to his roof which they never carried out.

They left him standing on the street, after driving him to withdraw the money, as they returned to 'trash' his house.

The man, who asked not to be named, said he wanted to prevent others falling prey to the heartless scammers, who had left him feeling depressed and afraid to leave his home.

"This was my life savings and all I have left now is my pension. I can't help blaming myself but they were so convincing. I just hope no one else has to go through what I did," he said.

The scam began on Friday, August 28, when he says two men knocked on his door and said the apex of his roof was damaged.

They told him they were working nearby and could carry out the repairs for £1,200, which he handed over.

On the following Tuesday, three men showed up and started putting ladders up. After a short while, they knocked at his door and told him the damage was worse than initially believed. They said the work would normally cost £14,000 but offered to do it for an extra £4,600.

Two of the men drove him to the bank to withdraw the money, which he gave them, while the third remained at the victim's house.

They then drove him to a property near Osterley station to show him an example of roofing work they claimed to have carried out.

But while he stood on the street inspecting the building they drove off, leaving him stranded.

"When I got home the place was trashed. I think they must have been looking for money but the only thing missing was the glossy card they'd given me with all the details of the company," he said.

PC Josh Lowther, of Hounslow CID, urged people to be cautious of cold callers and other possible scams.

He said people should avoid handing over cash before work is completed and should always do their own research to ensure people are who they claim to be. Anyone with any suspicions, he said, should call police on the non-emergency number 101.

"This was a disgraceful act of fraud in which they've targeted a vulnerable person for their profit," he added.

"I'm sure they're trying this at other locations within London. I just hope no one else falls victim to them."

* If anyone knocks at your door, you should always examine their identification and never let them in unless it is someone you know and trust. Call 101 if you have any suspicions.

If you are interested in what a door-to-door salesperson has to offer, always research their business and their offer before making any commitment, and never hand over a significant amount of money without seeking independent advice.

For more advice about scams and how to avoid falling prey, visit http://content.met.police.uk/Site/scamconstricksandfraud or pick up a booklet from your local police station.