One in eight of Bradford's hackney carriage drivers has been convicted of a crime.

And the range of offences committed by drivers includes violence, indecency, drug possession and dishonesty.

The statistics were uncovered during a lengthy Telegraph & Argus investigation.

Bradford Council's own figures show that of the 405 drivers licensed for hackney carriages by the authority, at least 50 have 151 convictions between them.

More than 80 date from before 1990, 59 happened between 1991 and 2000, and there have been ten since 2001 - these are shared by four drivers.

The full list of crimes contains offences of violence, indecency, dishonesty, drug possession, driving while disqualified, drink driving, careless driving, driving without insurance, arson and criminal damage.

The Council is unable to tell the T&A how many of the 1,900 private hire drivers it licences have convictions.

C D Khalid, the president of the Bradford Hackney Carriage Association, admitted he was surprised at the revelations.

But he said: "I would say hackney carriages are safe. We drive eight to ten hours and small things might happen on the road because we put more time in there."

And he claimed cabbies are often provoked into criminal behaviour by passengers.

He said: "Drivers are being blamed - if there are six passengers in a car the court will listen to the six."

Mr Khalid said drivers who have served sentences deserve a second chance, but he added: "As far as very serious offences are concerned the Council must be strict to be fair on those who are law-abiding."

The T&A investigation began after a series of high-profile incidents including revelations that a taxi driver with a previous conviction for assault was later jailed for a sex attack on a 15-year-old girl passenger, and a private hire driver had previously served a jail sentence for killing his wife.

Councillor Anne Hawkesworth, (Con, Ilkley) Bradford Council's executive member for the environment, said: "Our highest priority is to protect passengers and other road users and more than a year ago we tightened up procedures in issuing licences to try to ensure this."

She added: "We carry out regular roadside checks to ensure the drivers and their vehicles are complying with Council conditions and co-operate with the police, HM Customs and Revenue and other agencies in any campaigns they undertake. Anybody who breaches those conditions will be suspended and possibly prosecuted."

Councillor, the Reverend Paul Flowers (Lab, Great Horton), who sits on the Council's hackney carriages and private hire panel, called for a review of how licences are issued.

He said: "We need to have a debate about the sort offences that might disqualify somebody from areas of work with such responsibility.

"The vast majority of drivers are extremely good people, so it is in their interests that this issue is clarified."

Councillor David Ward (Lib Dem, Idle and Thackley) said: "It is the behaviour of people once they have licences that is crucial."