The prime minister of Belize has urged software company founder John McAfee to hand himself in to the authorities for questioning in relation to the death of his neighbour.
Mr McAfee went on the run after fellow American Gregory Faull, 52, was shot on the Caribbean island where they both lived.
Belize police have said he is a "person of interest" and prime minister Dean Barrow reiterated that he is only wanted for questioning.
But Mr Barrow also expressed doubts about the 67-year-old's mental state: "I don't want to be unkind to the gentleman, but I believe he is extremely paranoid, even bonkers."
It is understood Mr McAfee, who denies killing Mr Faull, has changed his appearance by dyeing his hair, eyebrows and beard and moustache black.
"I have modified my appearance in a radical fashion," he was quoted as saying by Wired magazine on Wednesday. "I'll probably look like a murderer, unfortunately."
Mr McAfee told The Associated Press from an undisclosed location that he had differences with the dead man.
"I barely knew him, I barely spoke 10 words to him in the last three years," Mr McAfee said, speaking on a mobile phone. "Certainly he was not my favourite person and I was not his.
"He was a heavy drinker and an annoyance. But the world is full of annoyances; if we killed all of our annoyances, there would be nobody left."
Other expat residents of the island of Ambergris Caye have described Mr Faull, the owner of a construction business in Orlando, Florida, as peaceful and well-liked.
The dispute apparently involved several dogs that Mr McAfee kept at his beachside villa and that drew complaints from neighbours.
Mr McAfee said four of his dogs were poisoned late last week but that he did not initially suspect Mr Faull of having killed them, although he knew he did not like the animals.
"He did threaten to shoot them once or twice," Mr McAfee said, adding that his neighbour was "always angry at them".
But he said he now believes government agents or police poisoned the dogs.
Mr Faull's body was discovered by a housekeeper on Sunday. He had been shot in the head but there was no sign of a break-in.
Police raided Mr McAfee's mansion that day to question him about the murder.
Earlier in the year, police searched the property for weapons and drugs, and detained him for several hours.
Mr McAfee sold his stake in the company that is named after him in the early 1990s and moved to Belize about three years ago to reduce his tax bill.
He told The New York Times in 2009 that he had lost all but \$4m (£2.5m) of his \$100m (£63m) fortune in the US financial crisis.