National police of Cambodia have opened an investigation into whether a U.S.-based charity allegedly with ties to LTTE, Phnom Penh Post said on Tuesday.

According to the newspaper the probe was conducted following sanction against the group by the U.S. Treasury Department.

"We are looking into the case" of the Tamil Foundation," national police spokesman Keat Chantarith told the paper.

On Feb. 26, the Cambodian Ministry of Foreign Affairs and International Cooperation sent a letter to Interior Minister Sar Kheng, requesting him to investigate the actions of the foundation which allegedly supported the LTTE.

The Foreign Ministry sent the letter after receiving a diplomatic notice from the U.S. Embassy warning of the existence of the U.S.-based Tamil Foundation.