A Keighley man has told how his late father invented a revolutionary tractor only to see his design "stolen" by government officials.

Deryck Feather claims his father Lance was never credited with the creation that helped the war effort in the early 1940s.

Lance, who ran a dairy from Knowle Top Farm, in Sutton, is pictured with the special double-gearbox tractor.

Deryck says hundreds of farmers, including some fellow villagers, built similar machines after seeing the design in a magazine.

In the years before the Second World War many farmers built their own tractors using parts of old cars, such as Morris 12s or Austin 16s.

What made Lance's vehicle different was that he used two gearboxes instead of one, allowing it to drive more slowly.

Deryck says the tractor drew the attention of agriculture officials when they visited his farm to discuss his wartime duties. He adds: "A few weeks later the sketches were published in Farmer's Weekly and they didn't credit my father.

"They were built all over the country and several people in the past have claimed to be the first to do it."

Lance gained some satisfaction against the government after the Second World War, when petrol was being rationed.

He used the tractor -- which was exempt from rationing because it was an agricultural vehicle -- to ferry his family across the hill to Keighley.

Lance parked the tractor at a friend's farm in Spring Gardens Lane and the family walked into town to go to dances at Britannia Hall.