BANGKOK: Prime Minister Prayut Chan-O-cha will this week make the first visit by a Thai leader to Saudi Arabia in more than 30 years following decades of diplomatic tension sparked by a jewel theft from a Saudi palace.
Thai-born janitor Kriangkrai Techamong stole US$20 million worth of precious gems in 1989 from the home of a Saudi prince, triggering a feud between the countries dubbed the "Blue Diamond Affair" that has yet to be resolved.
Thai police later returned some of the jewels but Saudi officials claimed most were fakes, while the whereabouts of the most precious gem - a rare 50-carat blue diamond - remains unknown.
The invitation to Prayut for a two-day visit beginning Tuesday was issued by Saudi Crown Prince Mohammed bin Salman, the Thai government said in a statement.
"This visit is the first visit by a head of government between the two countries in more than 30 years," the statement said.
Prayut will meet with the Saudi crown prince "to strengthen and promote bilateral relations", it added.
"The visit comes after consultations that resulted in convergence of views on many issues of common concern," the Saudi government said in a statement posted on the website of the kingdom's news agency.
Saudi Arabia has long accused Thai police of bungling their investigation into the theft, with allegations that the stolen gems were snapped up by senior officers.
Riyadh sent a businessman to investigate in 1990 but he disappeared in Bangkok days after three Saudi diplomats were shot dead in the city.
In 2014, due to a lack of evidence, a case was dropped against five men, including a senior Thai policeman, accused of involvement in the Saudi businessman's murder.
Saudi Arabia has not sent an ambassador to Thailand for decades and restricts travel between the countries.
Thailand has long sought to patch up ties in an effort to boost its tourism industry and widen job opportunities for Thai labourers overseas.
Kriangkrai served five years in jail over the jewel theft and sold most of the gems before his arrest. He then became a monk in 2016.
He said he turned to religion in an attempt to escape bad karma.