Antivirus software tycoon John McAfee, wanted in Belize for questioning over the murder of an American expatriate, has arrived in the US after being deported from Guatemala.

He entered the South American country illegally after evading Belize police, but a Guatemalan judge ruled that his detention was unlawful and he was put on a plane bound for Miami.

He arrived shortly before 7pm local time on Wednesday and US customs authorities reportedly escorted him to an airport taxi stand before he was driven to an upscale hotel in Miami's South Beach neighborhood.

The eccentric millionaire has been on the run for over a month after the body of Gregory Faull, his neighbor near his home in Belize, was found with a bullet wound to his head on November 10.

Faull had reportedly quarreled with McAfee over his dogs before the murder and police are interested in speaking to him as a "person of interest".

However, McAfee, who is famous for creating the McAfee Antivirus software, says he is facing political persecution in Belize after he refused to donate $2 million to the country's ruling party.

After arriving in Miami, McAfee posted of his arrival in Miami on his blog.

"I have no phone, no money, no contact information," the post, which has now been removed, said.

The 67-year-old has been living in Belize since 2010 where he relocated to run a startup company in the field of antibacterial medicine.

He has garnered intense media interest since going on the run, blogging his exploits online as well as providing extensive media interviews via online video streams protesting his innocence.

In the latest post on his blog, McAfee complains that he has been forcibly separated from his 20-year-old girlfriend Sam Vanegas and that he fears for her safety.

Belize has an extradition treaty with the US and it is likely that authorities will seek his return for questioning.

"I don't want to be unkind to the gentleman, but I believe he is extremely paranoid. I would go so far as to say bonkers," Belize's prime minister, Dean Barrow, told reporters. 

"He ought to man up and respect our laws and go in and talk to the police."