Heartless thieves have been using the Bingley Relief Road as an excuse to con vulnerable elderly people out of thousands of pounds in a road surfacing scam.

Gangs of itinerant traders turn up on the doorstep of pensioners' homes and claim they are working on the construction of the relief road, which finally opened last Monday.

They ask to leave a couple of spare drums of surfacing material with the pensioners while they are out working and then return and offer to replace their drive at cheap rates as a 'thank you' gesture. But West Yorkshire trading standards chief Paul Smith warned: "They say they will do the drive for £300 as a favour. But if the victim agrees, then the price goes up to £3,000 and they are told: 'We want it now, we'll take you to the bank'."

The callous gangs have been targeting the elderly in Bingley and Saltaire and trading standards officers have received several reports of the bogus traders using the relief road scam.

Mr Smith, principal officer for the fair trading section, said victims had been conned out of £5,000, including one elderly man who had lost £1,900.

But he said a rapid response team, which can be contacted on a special helpline and steps in while the traders are on the doorstep, has dealt with 95 cases since February and saved people £35,000. Mr Smith said: "If people ring the helpline, which they have been doing, and the conmen are at the house the rapid response team will go there straight away and negotiate on their behalf. "

Mr Smith said the problem they were dealing with at the moment was the itinerants using the relief road as their means of carrying out illicit work. He said: "These people are ruthless. They obtain money in any way they can. They don't care how vulnerable the person is."

He advised people to say no to the conmen. "Don't say you'll think about it because by the time you have they will be starting to work on your drive. If you say no there is nothing they can do.

The special helpline rapid response number at West Yorkshire Trading Standards is 0113 384 8848.