British Tour de France rider Luke Rowe faces a lengthy break from cycling after breaking his leg at his brother's tag party.

The Team Sky rider sustained fractures to his tibia and fibula following a rafting accident, according to the official Team Sky website.

"My brother Matt is getting married and so I was away with family and friends for his 'stag party'," Rowe said.

"On the first morning we went whitewater rafting. I jumped down into the water but landed in a shallow section on my right leg.

"Being a bike rider you get in a lot of scrapes and you get used to injuries, but I knew straight away that it was a bad one."

Rowe, who helped teammate Chris Froome to a fourth Tour de France title this year, faces a decent break off the bike.

"It's been a big shock and I know I've got a long period of recovery ahead," he said.