Opposition newspaper editor Dam Sith was still in jail Tuesday, despite a request from the Ministry of Information Monday he be released and hopes for international intervention by local rights groups and the opposition.
A Phnom Penh Municipal Court judge said Tuesday he was considering the ministry's letter.
Opposition leader Sam Rainsy called the arrest "very unjust and illegal."
He placed a call to US Ambassador Joseph Mussomeli on Sunday, after the arrest of Dam Sith, editor of Moneaksekar Khmer, Sam Rainsy said. The ambassador said he would intervene, Sam Rainsy said.
The US has not written a letter to Phnom Penh Municipal Court to intervene, US Embassy spokesman Jeff Daigle said Tuesday.
"I can say that the embassy is concerned about the case, and we are following it, and we feel that it is regrettable that Dam Sith was detained," Daigle said.