Facial recognition will be deployed at a marathon on Sunday in China to crack down on cheating, state media said, after a half-marathon was blighted by widescale flouting of the rules.

Running and marathons are fast becoming popular in China, with participants sporting the latest trendy gear and wearable technology.

But the sport has also made unwelcome headlines and a half-marathon last weekend in Shenzhen later found that 258 runners had cheated, including many who took shortcuts.

Chinese authorities have now vowed to get tough.

For this Sunday's Kunming Marathon, which is expected to draw 6,000 runners including foreign athletes, organisers will use facial recognition to ensure people do not get someone else to run for them.

"Competitors must carry a valid ID and carry out verification through the facial-identification system," Xinhua news agency said.

Xinhua on Thursday called the cheating at the run in Shenzhen, over the border from Hong Kong, "deeply shameful".

China has been rolling out facial recognition across the country for everything from fast-food orders and airline check-ins to catching criminals.