Fiji police are analysing a video which appears to show fishermen being shot dead at sea by unknown gunmen.
The 10-minute video - which was uploaded to YouTube by an unknown source - shows the men clinging to the remains of an upturned boat as shots are fired from what appears to be a commercial vessel.One of the commercial vessels seen in the video
The film shows some of the men on the boat, which appears to be a tuna fishing vessel, laughing and posing for photographs after the killings.
Interpreters said languages heard on the video included Mandarin, Thai and Vietnamese, while the markings on one of the boats reportedly identify it as Taiwanese.
Fiji Police spokesman Atunaisa Sokomuri said it was too early to confirm whether the footage was genuine.
"There is no clear evidence to identify the victims as Fijian citizens, nor is there a clear indication of where or when this gruesome incident took place," he said.
The president of the Fiji Tuna Boat Owners Association, Graham Southwick, told Pacific Beat radio that Taiwanese boat contractors in Suva have claimed the footage shows the aftermath of a failed hijacking off Somali last year.Men on the vessel laughed and posed for pictures after the killings
"It's a very famous incident and this didn't happen in Fiji, it happened off the coast of Somalia," he said.
"And the graphic pictures you see of people gunned in the water are not Fijians, but Somali pirates that attempted a hijack of some Taiwanese vessels that attempted a hijack that backfired and they all got gunned down.
Authorities have asked for help from Interpol and other Pacific nations to identify the vessels seen in the video.
Fairfax Media New Zealand, citing Fijian police sources, has reported that a student found the footage on a mobile phone left in a taxi in the Fijian capital, Suva.
Fiji is home to a large tuna fishing fleet, with many of the vessels from so-called "distant water" nations who ply the Pacific because it is one of the few regions where stocks, though declining, are still relatively abundant.