A Chinese tourist was stabbed in a violent row over his penis size.

Zhang Haotian, 24, was walking with his Thai girlfriend, 35, when he was reportedly insulted by a rude local along a beachside road in Pattaya, Thailand, in the early hours of January 20.

The provocateur, said to be a Thai man, allegedly asked Zhang about his penis size as the Chinese boyfriend told him his manhood 'had nothing to do with him'.

The remark soon escalated into a full-blown punch-up, with the Thai man allegedly jamming a key into Zhang's arm before running away.

Footage shows Zhang bleeding from the puncture wound on his right arm. The blood seeped through and stained his grey shirt.

Miss A took her boyfriend to the local police station to file a report.

Police Major Suthiraphan Tapsri, investigator at the Pattaya City Police Station, said: 'The police coordinated with a local rescue unit to provide first aid to the Chinese boyfriend. We have recorded his statement for evidence and we will take legal action against the perpetrator.'

Global data compendium Data Pandas, citing a 2014 study published in medical journal BJU International, said Chinese men have an average penis length of 12.9cm (around 5 inches) when erect. Men from the United Kingdom averaged 14.3cm (5.6 inches) and those from the United States averaged 14.15cm (5.57 inches).

Sudan and the Democratic Republic of Congo, toppled the table with lengths of 7.06 inches and 7.05 inches.

The disturbing incident is the latest issue with tourists in the bustling coastal city, where round-the-clock sex workers cater to holidaymakers.

Government chiefs have attempted to clean up the city but regular violence and depravity continue to blight its reputation.

In December, a British tourist, 71, was grilled by police after he admitted sleeping with the the corpse of a dead prostitute for three nights before the body was discovered.