A Railtrack undercover operation got off to a bad start - when the company was forced to reprimand one of its own workers.

The first trespasser caught in an initiative to catch track trespassers turned out to be an off-duty Railtrack employee.

The man and two children were spotted at Kennington junction, walking down a lane towards two locked gates, heading for a fishing trip.

Operation Rhino was jointly launched by Railtrack and the Transport Police to combat the traditional rise in trespass during the school holidays.

Graham Wells, of Railtrack, who was on the operation, said: "He should have known better."

Signs at the junction warn that trespass carries a 200 fine but police let the Railtrack employee and his children off with a warning.