Last updated on .From the section Cycling

Froome led the Tour de France by 12 seconds going into Monday's first rest day

Tour de France 2015 Dates: 4-26 July BBC coverage: Live text commentary of every stage online and radio commentary on BBC 5 live sports extra or online from 14:45 BST

Team Sky believe their computers have been hacked by critics convinced Tour de France leader Chris Froome is using performance-enhancing drugs.

Froome has been subjected to sustained scrutiny since his Tour win in 2013, with some sceptics using power data to justify their case against him.

The 30-year-old Briton has always insisted he is a clean rider.

"We think someone has hacked into training data and got Chris's files," said Team Sky boss Sir Dave Brailsford.

"We've got some legal guys on the case. I would never mention a name but ethically and morally if you are going to accuse someone of doping, then don't cheat."

Tour de France 2015 - General classification standings 1. Chris Froome (GB) Team Sky 31hrs 34mins 12secs 2. Tejay van Garderen (US) BMC Racing +12secs 3. Greg Van Avermaet (Bel) BMC Racing +27secs 4. Peter Sagan (Svk) Tinkoff - Saxo +38secs 5. Alberto Contador (Spa) Tinkoff - Saxo +1min 03secs

Froome said critics on social media who try to interpret power data are "clowns", adding that it means nothing without context. He has also said he is prepared to be a spokesman for drug-free sport.

With Froome leading this year's Tour by 12 seconds going into Tuesday's 167km 10th stage, Brailsford says he is braced for more questions over doping.

"It's part of the game, isn't it?" he said. "If he does well [on Tuesday], the rest of the Tour it's 'how do you know he's not doping?'

"The question of how to prove a negative is always going to be a difficult one.

"I used to worry about it a lot more, but I don't any more. It's part of the game. Just try to be honest, tell the truth, be open."