PHUKET: ''Rambo'' killer Joseph Manuel Hunter, arrested on Phuket, has pleaded guilty to conspiring to murder a law enforcement officer and two other charges, news agencies report.

The 49-year-old decided to avoid a trial scheduled for March for the sake of his family, a defence lawyer said after the guilty plea in New York federal court on Friday.

Prosecutors said Hunter worked as a killer-for-hire after leaving the US Army in 2004 and arranged for several murders before his arrest at a bungalow on Phuket. Details of any killings are not publicly known, Reuters news agency reported.

In a series of meetings in 2013 in Asia, Africa and the Caribbean, Hunter met the two undercover agents and agreed to serve as head of security for their cartel, according to court documents.

He assembled the team of former soldiers and began providing a variety of services to the supposed cartel, prosecutors said.

Hunter is the fourth defendant to plead guilty after former U.S. Army Sergeant Timothy Vamvakias, former German sniper Dennis Gogel and former Polish sniper Slawomir Soborski.

Hunter faces between 10 years and life when sentenced in May.

The fifth man charged in the case, Michael Filter, a former German military sniper, is scheduled to go on trial on June 1.