A decapitated head that washed up on a paradise beach belongs to a tourist who went missing with his wife last month, police believe.

Detectives probing the mysterious disappearance of Yuri Shipulin and his wife Natalia, who lease a farm on the island paradise of Fiji, reckon the pair were murdered.

The couple, described as 'soul mates' who were both photographers, haven't been seen since mid-June in the South Pacific nation.

Several body parts washed up on the popular Natadola beach last month - including dismembered feet weighed down with rocks and wrapped in a fishing net.

Police are investigating the mysterious disappearance of Yuri Shipulin and his wife Natalia (
Image:
ONE News/Facebook)

And this week a horrified tourist found a decapitated head that matches DNA samples belonging to missing Yuri.

New Zealander Graeme Bickley told ONE News he and his wife Jan saw a bundle in the water while they enjoyed an ocean walk.

He said: "I went out in the tide and it was in knee depth water and grabbed it, it looked like a little bundle but it was very heavy of course.

Police and navy are searching for more remains on the coast line (
Image:
ONE News)

"It was slightly bigger than the steering wheel and completely round and full of rocks," Mr Bickley said, adding that the grisly find left "a funny feeling in the tummy."

A friend and fellow Russian Alla Mallerich, told the Fiji Times the pair were "soul mates".

"Yuri was a happy, easy going man who loved life, loved Fiji and he had plans to build his life in Fiji," she told the newspaper.

Specialist forensic divers have been called in to look for more body parts (
Image:
ONE News)

Social media pictures show the couple looking happy and enjoying drinks in the sunshine.

But business partner Andrew Luzanenko, who co-managed the farm, told the Fiji Sun that the farm was devastated by Cyclone Winston earlier this year, causing severe financial problems.

Chief of Intelligence and Investigations, assistant commissioner of Police Luke Navela, said: "DNA tests conducted confirm the remains belong to the two. Investigations continue."

The Russian couple’s business partner reported them missing and their vehicle was found on a road near the coast a few days after they disappeared.

The grey Toyota Land Cruiser, with the registration ‘PILOT’, was seen driving to Natadola Beach.

Police found the vehicle parked under trees at the beach, unlocked and with the keys still in the ignition.

Officers found women’s clothing, believed to be the outfit Natalia was wearing the day beforer she went missing, and a passport.

The pair have been in Fiji since 2011 and leased a farm, as well as running a photography business.

The results of tests carried out in Fiji were sent abroad for DNA tests with the help of Interpol.

The Fiji Navy is helping police search the water for more body parts.