Hundreds of undelivered letters have been found dumped in a Bradford quarry.

It is at least the fourth instance of mail discarded in Bradford over the past two months.

In the latest incident children found two large bundles of mail in Parker's Quarry, Heaton.

The letters, all addressed to the Brad-ford 9 area, were retrieved and taken to the Bradford North sorting office.

Over the past few weeks undelivered mail in Bradford has been found:

l dumped in a pond in Peel Park

l abandoned in bushes

l left scattered in the street.

One Royal Mail employee, who did not want to be named, told the Telegraph & Argus that a casual postal worker had been escorted off the premises by management in connection with the incident.

"This has just gone beyond a joke," said the employee.

"Week by week this is going on.

"I was talking to one of the managers and asked them 'What training is being given to casual staff?' 'Absolutely none', he said, 'they aren't employed by us.'

"The temporary staff aren't vetted and there are security implications here.

"My main concern is why the management isn't tackling the problem."

A Royal Mail spokesman apologised to customers for delays caused by the dumped mail and said the incident was being investigated.

But he denied that casual staff were not trained.

"There are people who work on and off when required often during holidays and periods of sick absence," he said.

"If we can't get enough people we then go to agencies to fill in the gaps.

"We've always done that and will continue to do so. If anyone working for us is found not to be suitable we would take the necessary action to make improvements in performance or not to use them again.

"Agency staff are trained. They don't go out on their own initially."