Farmers are being investigated for selling cattle banned for human consumption in the wake of the BSE affair.

In a practice known as "cow clocking" some farmers across the country are being accused of forging the age of cattle so they can sell it on for food.

Two North Yorkshire farmers are being investigated by trading standards officers.

Graham Venn, a North Yorkshire trading standards chief and chairman of the National Animal Health and Welfare Panel, told the Evening Press: "These cases are going on all over the place."

Mr Venn warned farmers and dealers that trading standards officers were keeping a watch on their practices.

He confirmed two farmers in North Yorkshire had been prosecuted. Both were given a conditional discharge.

He warned: "We will be diligent and if we find that any unscrupulous trader or farmer is trying to get a few hundred pounds by putting in an animal into the food chain that is over 30 months, then we will prosecute."

He said only a minority of farmers were involved and many of these cases were due to sloppiness rather than deliberate forgery.

"There are a few farmers out there that still don't like paperwork and until they grasp the fact that they have got to be careful and diligent with paper work and identify animals, there are always going to be problems," he said.

"There has got to be a change of attitude on the part of farmers."

Elizabeth Levett, from City of York trading standards, said the practice was "quite widespread".

Under laws brought in after the BSE crisis, cattle can only be sold for food if they are less than 30 months old.

Trading Standards officers say some farmers are claiming that identification tags from cows' ears have been lost and are then applying for new documentation.

They then forge the animal's date of birth on the application form for a new "cattle passport", so that it appears to be less than 30 months old. The practice can only be detected by examination of the animals' teeth as they tend to have more teeth as they get older.

Farmers are supposed to have cattle more than 30 months old incinerated, receiving £300 in compensation.

"We have had one successful prosecution against a farmer two years ago, but it is still going on and the indications unofficially are that it may be quite widespread," said Mrs Levett.

She said the department was informed every time a farmer applied for new passports and ear tags and investigated where a farmer seemed to be getting lots of new ear tags. Officers also routinely visited markets and farms to inspect ear tags, checking for signs of tampering and of the tags being defaced. The maximum penalty for the offence is £5,000.

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