AVARUA (AFP) - An escaped prisoner who murdered two people in the tiny Cook Islands reportedly killed himself after a stand-off with the police on Thursday (Oct 20), ending a crime spree that shocked the Pacific island nation.

The main island of Rarotonga went into lockdown on Wednesday when Chris Rimamotu fled from a prison work detail, with the police advising residents to stay indoors.

The convicted sex offender then killed two people and went on the run as the police launched an island-wide manhunt.

The Cook Islands News reported that Rimamotu holed up in an abandoned house on Rarotonga and shot himself on Thursday morning with the property surrounded by police.

Police would not confirm his death, saying only: "The situation with Chris Rimamotu has been contained. It is now safe for the community in regards to this matter."

Serious crime is rare in the Cook Islands, a nation of just 10,000 people about 3,200 kilometres (2,000 miles) northeast of New Zealand.

In 2011 it recorded its first-ever bank robbery on the remote island of Aitutaki.

Witnesses said Rimamotu's victims were his former partner Mary Dean and her new boyfriend Roger Tauarea.

Ms Dean is believed to have been strangled while Australian holidaymaker James McPhail, who was in a neighbouring property, said Mr Tauarea was shot up to 20 times in an "execution style" killing.

Mr McPhail said Mr Tauarea ran into his garden in a bid to escape the gunman but Rimamotu chased him down.

"He walked very calmly, he looked very cool and collected," he told AFP.

The Australian described the experience as horrific and extremely distressing.

"It is unbelievable really, it was so peaceful and beautiful in the garden," he said.