Michael O’Driscoll was taken to court by Wandsworth Council after trying to swindle the pensioner out of tens of thousands of pounds.

He told her that her house needed complete refurbishment from top to bottom, including rewiring, replumbing, new windows and a new roof. His price for doing all this work was £38,000.

But his ruse was uncovered after the victim's bank manager became suspicious and an independent surveyor checked the quality of the work O'Driscoll had actually done. It was found that none of it was necessary and what little Mr O’Driscoll had completed was nothing more than a substandard ‘bodge job’ that would need further work putting right.

The surveyor examined timber supports that the 44-year-old conman had installed in the roof. He described these as “quite clearly utterly pointless” and judged that they had actually endangered the roof’s integrity by putting additional weight onto parts of the structure not designed to bear weight.

He concluded that the “crude and haphazard” work had been carried out by someone “with no knowledge of structural design or loadings and for no apparent reason”.

At best the estimated value of the work O'Driscoll completed was around £750 and that if everything that needed doing had been done properly, it should have cost no more than £6,000. Yet Mr O’Driscoll was trying to charge the pensioner £38,000and had persuaded her to pay £27,000 into a bank account he controlled.

His con-trick was rumbled by a customer services manager at the Tooting branch of Lloyds Bank who grew suspicious when Mr O’Driscoll came into the bank, accompanied by his victim, and tried to withdraw the £27,000 in cash.

Staff at the bank called the council’s trading standards team and two officers were immediately sent to the branch where they intercepted Mr O’Driscoll and with the bank’s co-operation were able to prevent any money being handed over. The £27,000 was subsequently returned to the victim.

It was later discovered that he had already received around £8,000 from the victim but this money had vanished and there was no prospect of retrieving it.

It also emerged that the initial contact between Mr O’Driscoll and the victim had occurred after she was “cold called” and agreed to have a minor drainage problem fixed. After that, the list of repairs he’d said needed doing had grown and grown.

Jailing him for a total of 30 months at Kingston Crown Court on Tuesday, Her Honour Justice Topping described his crime as “a very mean offence indeed” and highlighted the fact that the fraud had been carried out over a prolonged period of time, was of high value and the victim was particularly vulnerable.

During sentencing the court heard that Mr O’Driscoll was in the middle of serving a 100 hour community service order after being convicted last August of stealing lead from the roof of a property in north west London. The judge was told that he’d gained access to the roof by offering the home owner a free quote on any repairs the building might need.

The judge also disqualified him from being a company director for five years. Mr O’Driscoll, of Masons Avenue in Harrow had been the sole director of a company called Grand Design Property Maintenance Ltd. In total he pleaded guilty to eight offences ranging from fraud to breaching consumer protection laws and unfair practice regulations.

The council‘s spokesman on trading standards and consumer protection Cllr Jonathan Cook said: “This was a despicable and heartless crime that targeted an elderly and vulnerable woman’s life savings. An immediate jail term was absolutely the right sentence in this instance.

“Tribute must be paid to the manager at Lloyds who initially spotted this fraud and also to the incredibly swift response of the trading standards team who managed to apprehend Mr O’Driscoll before he was able to flee the scene.

“This case should serve as a serious warning to any other rogue traders who are tempted to try and operate in Wandsworth. If you try and con people out of their money, there is a good chance you will be caught and when this happens we will not hesitate to prosecute you and demand the courts impose tough sentences for your crimes.”

Cllr Cook also repeated previous warnings to residents to remain on their guard against cold calling rogue builders and doorstep con-artists.

He said: “It is really important that people are extremely wary of traders who knock on doors unannounced and offer to fix things.

“Anyone approached by this type of cold caller should be on their guard. No reputable firm will try to drum up business in this way and none would ever insist on being paid in cash.

“Before agreeing to any type of building work householders should always try to get a second quote and seek professional advice before signing any contract.

“Traders who simply turn up and offer to do the job there and then will almost certainly be up to no good.”

Residents who are unsure about the identity of an unannounced caller should call 999 immediately. Concerns can also be reported to the council’s trading standards team on (020) 8871 7720 or by emailing tradingstandards@wandsworth.gov.uk.