A Chinese marathon race has ended in chaos after more than 250 runners were caught cheating, including dozens who took shortcuts.

Police footage has captured how some of the contestants ran across a traffic barrier filled with trees instead of jogging alongside it until they were able to make a U-turn.

The act potentially helped them shave two or three kilometres (1.2-1.8 miles) off the 21-kilometre distance (13 miles) during the Shenzhen Nanshan Half Marathon on Sunday.

More than 250 runners were caught cheating during the Shenzhen Nanshan Half Marathon on Sunday. In the file photo above, runners compete during the 2014 Shenzhen Marathon

Shenzhen traffic police released a footage on Sunday to show how the cheating runners cut corners. They ran across a traffic barrier filled with trees instead of jogging alongside it

A total of 46 runners were found to have cut corners and their act was exposed by Shenzhen traffic police in a social media post on the same day.

Another 190 runner cheated in various other manners, the race's organiser said in a statement yesterday.

In addition, 18 people had fake bib numbers and three ran in someone else's place.

All of the 258 offenders have been penalised.

Those who faked registration numbers or hired other people to run in their place were deemed to be the most serious offenders and will face lifetime bans from the race. The others will not be allowed to take part in the race for two years.

The organiser urged runners to follow the rules, respect other contestants and the athletic spirit.

258 offenders have been penalised by the organiser of the Shenzhen Nanshan Half Marathon. In the file photo above, runners wear different costumes in 2014 Shenzhen Marathon

Commenting on the incident, China's state news agencyXinhua branded it 'deeply shameful'.

The report said: 'No matter the participants or the organisers, they should reflect: What is the significance of participating in and holding marathons?

'Don't run and forget why you run. Don't let the marathon turn sour.'

The news comes less than two week after Chinese national marathon runner He Yinli unwittingly sparked a national debate about patriotism during a race in eastern China.

A volunteer gives Chinese athlete He Yinli a national flag at Suzhou Taihu Marathon last week

Controversy emerged after an overly enthusiastic volunteer darted onto the course to hand He a Chinese flag as she vied for victory at the Suzhou Marathon earlier this month.

She briefly held onto it before letting it fall to the floor, explaining later that it had slipped from her grasp.

Some Chinese internet users questioned He's patriotism for dropping the flag, but many others faulted the volunteer for interfering.

He Yinli was beaten to the line by Ethiopian Ayuntu Abera Demisse after the fiasco.