Two handguns believed to have been used in last week's murder of Indian gangster, Jimi Singh Sandhu, have been discovered in the sea off a beach in Phuket close to the crime scene.
The two suspected gunmen reportedly fled the country on Sunday.
National police chief Suwat Jangyodsuk arrived in Phuket on Thursday to attend a meeting aimed at wrapping up the case. Sandhu, also known as Mandeep Singh, who was shot dead in front of his villa on Rawai Beach at about 11pm last Friday. His body was discovered the next morning.
He is known to have been deported from Canada in 2016 and was a member of a criminal gang involved in illicit drug cases and other crimes, including several assaults and for illegally owning firearms.
All of the evidence in the latest case including state documents, forensic tests, CCTV footage and the identities of the suspected gunmen was discussed in the meeting, also attended by Pol Lt Gen Amphon Buarapphon, the commissioner of Provincial Police Region 8, and other officials.
According to the police report, two handguns -- a CZ 9mm semi-automatic and Walther 9mm fully-automatic -- were pulled from the sea at a nearby beach at 2.30pm on Thursday. Each was legally registered under the name of a Thai national.
Police said they will summon the gun owners for questioning about their involvement in the case.
From their preliminary investigation, police said they have determined both gunmen are Canadian and left Thailand on Sunday.
Deputy police spokesman Pol Col Kissana Phathanacharoen said investigators are waiting for forensic results and gathering more evidence before they seek arrest warrants against the two and other accomplices.
Meanwhile, Chalong police detained a 33-year-old Russian man for questioning on Thursday after he was spotted setting up a GPS system on the dead man's car at a house in tambon Rawai. Unspecified amounts of ketamine were also discovered at the same property.