World’s deadliest sniper is a Royal Marine

The corporal is believed to have killed at least 173 people

A sniper secures as area during the 16 Air Assault Brigade Exercise Joint Warrior at West Freugh Airfield, Stranraer, Scotland on April 16, 2012. (PETER MUHLY/AFP/Getty Images)

The world’s deadliest military sniper is believed to be a Royal Marine.

Having served for the Royal Navy’s elite unit for over a decade, the majority of his 173 kills were recorded in Afghanistan in 2006 and 2007.

The unnamed corporal, who is reportedly married and from southern England, also served in Iraq, The Sun reported.

His staggeringly-high number of kills, which a source told the newspaper was "conservative", makes the Britain more lethal than Chris Kyle. The US Navy Seal, who had a confirmed 160 kills, is the most lethal sniper in the US.

Kyle exploits have sparked controversy, after he detailed his approach to the job in his book 2009 American Sniper.

"There's another question people ask a lot: 'Did it bother you killing so many people in Iraq?' I tell them, 'No.' … I loved what I did. … I'm not lying or exaggerating to say it was fun."

More recently, the American Sniper Hollywood biopic of Kyle, who was killed in 2013 on a shooting range in the US, has been nominated for two Oscars and has been a hit at the US box office, making £166m (249m dollars) in only three weeks of cinema release.

But the Clint Eastwood-directed film has faced criticism that the film glorifies murder and serves as war propaganda.

Left-wing film maker Michael Moore is among the critics, and called snipers "cowards" after his uncle was killed by a Japanese sniper in WWII.

A source told The Sun that the British sniper is "not interested in scores or kill counts".

"He took no satisfaction in the job he had to do," the source said, adding: "Every shot was judged and balanced, not indiscriminate. He always saw the men between the cross hairs as humans not as targets."

"He had a unique job at a unique time. He must be the most lethal sniper in the world. But that is not a title he would seek out or revel in," the source added.