Five Cambodian fisherman have confessed to raping and assaulting French tourists on an isolated Thai beach, Cambodia's foreign ministry said in a statement on Tuesday.

Thai police said four French tourists were attacked late on Saturday on Koh Kood, a remote island near Thailand's maritime border with Cambodia known for its untamed jungle and pristine beaches.

Thai police investigators said the attackers swam from their fishing boat to assault the group and raped two women at knifepoint. They were caught while trying to escape.

Cambodia's Foreign Affairs Ministry said in a statement that the five fishermen confessed to Eat Sophea, Cambodian Ambassador to Thailand, that they raped and assaulted the tourists.

"During the interview with the Cambodian ambassador the five fishermen confessed to have really been involved in the cases of rape and assault," the ministry said in a statement.

"It happened while the five fishermen were in a drunk state."

The five have been charged with rape and violent assault.

It is the latest high-profile case to hit the popular holiday destination, raising serious questions about tourist safety in the Southeast Asian country.

In December, two migrant workers from Myanmar were found guilty by a Thai court of killing two British tourists on a beach on the southern Thai holiday island of Koh Tao in 2014.

Thailand remains a popular tourist destination, despite a slew of high-profile crimes against tourists last year and an August bomb attack at a popular Bangkok shrine that left 20 people dead, most of them foreigners.

The government expects a record 32 million people to visit Thailand this year. Tourism remains one of the few bright spots in the Thai economy which has struggled since a 2014 coup by the military.