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Bangkok, Thailand (CNN) -- A British kickboxer is on the run from the law in Thailand after he allegedly stabbed a U.S. Marine to death after a bar brawl last week.
The fugitive, Lee Aldhouse, is believed to be hiding in the popular tourist destination of Phuket, where the incident took place, Phuket police Lt. Col. Anukul Nooket told CNN on Tuesday.
Police have sent a photo of Aldhouse and a copy of his passport to every immigration checkpoint in Thailand, Chalong police Col. Vichit Inthasorn said.
"We are doing everything we can to stop this guy from leaving the country, but there are chances that he might have slipped through neighbor countries via other small islands," Inthasorn said.
Aldhouse and the American, Dashawn Longfellow, began to quarrel at Freedom Bar in Phuket's resort area of Rawai Beach, said Nooket, who is heading the investigation. Then, when Longfellow headed toward the men's room, Aldhouse followed him and a fight ensued outside the restroom, with the American punching the Briton to the floor before the men were separated, according to Nooket.
Both men were trained kickboxers adept in the popular local Muay Thai style, Nooket said. Muay Thai involves using the fists, elbows, knees, shins and feet.
"It was simply a fight between two bad-tempered young men, and both were good at Muay Thai, and things became out of hand," Inthasorn said Tuesday.
Nooket said that when Longfellow and his Thai girlfriend returned to his rental home, Aldhouse came from behind and fatally stabbed Longfellow.
Police have issued an arrest warrant for Aldhouse, based on what they consider strong eyewitness evidence from Longfellow's girlfriend, Nooket said.
Investigators also are considering surveillance video from a 7-11 convenience store as evidence, Inthasorn said.
"The full footage obtained from [a] 7-11 shop showed ... Longfellow and his Thai girlfriend entered the shop and the prime suspect Lee Aldhouse was [in] the same shop, too," Inthasorn said.
Aldhouse has been living in Phuket for years, according to the Naiharn Boxing Club, where the Briton had trained until last year.
Nooket said that Longfellow's relatives are traveling to Phuket to meet with police Thursday.
Longfellow's sister, Sabre Anderson, told CNN affiliate KMGH on Sunday that while Longfellow was born in Colorado, he had grown up in Norman, Oklahoma. Longfellow's mother told CNN affiliate KWTV he joined the Marine Corps after graduating from Norman High in 2005, hoping to travel the world.
Family members told KMGH that Longfellow was a decorated Marine who served in Iraq and Afghanistan.
Anderson set up a Facebook memorial page in her brother's honor, where she wrote, "Dashawn was killed in cold blood on the 12th of August 2010. He didn't deserve to die like this. He served two tours in the war, got two Purple Hearts after being hurt by his vehicle exploding while he was there and going back to save who he could. He was awarded many more medals. The bastard who took his life must be punished. He must be found. R.I.P. Dashawn you will forever be loved."
CNN's Kocha Olarn contributed to this report.