Jumping the train might seem a victimless crime, but it costs rail firms �40m a year.Last night ticket inspectors and police launched a crackdown on fare dodgers on the King's Lynn to London line, with platform checks at busy Downham Market station.

Jumping the train might seem a victimless crime, but it costs rail firms �40m a year.

Last night ticket inspectors and police launched a crackdown on fare dodgers on the King's Lynn to London line, with platform checks at busy Downham Market station.

Half a dozen teenagers who neglected to buy a �1.80 ticket before hitching a ride to Lynn Mart found themselves - or more likely their parents - �20 worse off, when they arrived on the 16:08 to find station exits blocked by a uniformed reception committee.

Gavin Vanns, a revenue inspector with First Capital Connect, said: “They got a free journey to Lynn, so they thought they'd got away with it - they got a bit of a shock when they got off the train.”

Mr Vanns said under-18s could expect a �20 fixed penalty ticket, while adults would be prosecuted if they could not pay the �20 or 10 times the single fare for the journey on the spot. He said checks at Downham and other stations on the Lynn-London line would continue.

“Depending how it goes today, we'll be doing it every now and then and there'll be not set pattern to it,” he said.

Train operators like First Capital Connect are reluctant to speculate on the amount fare dodgers cost them in lost ticket sales, now trains rarely have a ticket collector on board.

“Industry-wide, it costs upwards of �400m a year that could be invested into new trains, stations and things like that,” one senior rail source said. “Why should fare paying passengers have to pay for those who refuse to.”

Colin Sampson, chairman of FLUA (the Fen Line Users Association) said: “As far as I'm concerned they should all be caught, fined or jailed.

“If all these people paid their whack we wouldn't quite see nil fare increases but there'd be a better deal for the rest of us.

“FLUA would like to see revenue inspectors on every train and more stations staffed for longer. It's a problem all over the system, not just on this line.”