The body was found in the island's Thalang district Saturday. The Russian property developer disappeared from his home on March 7.
He is believed to have been abducted with his girlfriend, 23-year-old Russian Yana Strizheus, who was later found in a resort. Police discovered the body while searching for the suspected abductors.
Local media sources reported Provincial Police Commander Ong-art Phiwruangnont as saying the suspects - Oleksandr Boychuk, 44, and Aleksandr Novichkov, 58 - had rented a house in Soi Koktanode in Cherng Talay.
"We dispatched 40 officers and specially trained police sniffer dogs brought in from Nakhon Si Thammarat to search the area," he said.
"At 1pm today, I received a report that the body of a foreign male was found at a lagoon near the suspects' rented house.
"We believe the body is that of Mr Salbinskiy as the sniffer dogs found the remains while searching the area using scent from Mr Salbinskiy's belongings."
The body was sent for forensic examination.
Ms Strizheus sustained multiple external injuries, mainly to the neck. She also appeared weak when she was discovered.
Phuket Provincial Court have issued arrest warrants for Mr Boychuk, a Ukrainian, and Mr Novichkov, a Russian national.
The two are wanted in connection with the alleged kidnapping of Ms Strizheus. The suspects are facing charges of illegal detention, robbery and attempted rape.
The search team checked the area in tambon Cherng Taley after questioning Ms Strizheus.
Cherng Taley is where Ms Strizheus was discovered injured in a hotel room on March 16, more than a week after the couple were reported missing. Local police and border patrol police from Nakhon Si Thammarat took part in the search operation for Mr Slabinskiy.
Relatives and friends of Mr Slabinskiy recently offered a cash reward of 500,000 baht for any information leading to the arrest of the two kidnappers.
The investigators believe the suspects are still hiding on Phuket.