Koon Khmer

National police's anti-technology crime department arrested an American national and sent him to the Court in the afternoon of March 25 2017 on charges of extortion (reputation damage).

The suspect has been identified as Mark Alan Vandewater, a 67-year-old American businessman who has been living in Cambodia for a while.

Following a source at the Phnom Penh Municipal Court:
On May 18 2017 the suspect sent an e-mail (in English) to a friend demanding 10K USD; if the friend didn't come up with the money he would inform the friend's Vietnamese wife about his relationship with a Khmer woman.

After the 5th mail (it looks like the suspect sent 5 emails over the course of several days demanding 2000USD each time; the article isn't really clear on that) the friend decided to file a complaint and ask the police's anti-technology crime department to take action against the suspect.

The police investigated the case and arrested the suspect at Kirirom restaurant which is situated in Phnom Penh's Chamkar Mon district.

Police haven't officially confirmed the reports.

The case is currently in the hands of the Court.

Could it be him (on a bad day)

Born on August 05, 1949 and @ The Office Bar on Street 118 isn't unknown to him...

On May 18 2017 the suspect tried to blackmail his victim, an American man, for 10,000USD.

The sender of the email ordered his victim to make 5 wire transfers of 2,000USD each. (possibly through a money transfer service)

The victim got scared and filed a complaint after receiving the blackmail threat.

In the morning of May 27 2017 Mr.Vandewater has been charged under art.372 and 373 of the Criminal Code. (Blackmail)
Blackmail is punishable by an imprisonment from 2 (two) years to 5 (five) years and a fine from 4,000,000 (four million) Riels to 10,000,000 (ten million) Riels.
It's unclear whether he has been released on bail or not.