Shaun Barnes' family believe he had made a one-off decision to take the most direct route home and walk along the tracks from Lynn to Watlington when he was killed alongside his friend Luey Storr, also aged 17.

Mum Lynne Lasenby said: "I genuinely believe this was the first time he had walked along the tracks. I've asked all his friends and none of them said he had ever done it before."

Shaun had been cautioned for leaping onto the outside of trains at Watlington Station, where he and friends would often hang out some months before his death, but Mrs Lasenby said she believes he had learned his lesson.

"He did regret it afterwards," she said. "It was just something silly he did. Some of his friends have told me it wasn't even him, but he took the rap not wanting to be a grass."

Shaun, who lived with his mum and family in Wensum Close, Watlington, and Luey were killed by the 5.56am Lynn to King's Cross, London, service on Saturday, December 8.

Their bodies were not discovered until 8.30am when a driver travelling in the other direction spotted them near the line.

Mrs Lasenby is hoping a memorial bench will be placed on Watlington Millennium Green in Shaun's memory and will encourage youngsters not to hang around at the station.

Collections have also been gathered for a number of memorial sports trophies which are being made for football teams Shaun played for over the years and his former school, Downham High School.