The decision comes amid what rights groups have described as a government crackdown against the political opposition. Courts have already banned the main opposition party and 100 lawmakers from office.
A Cambodian court ordered authorities to temporarily seize the headquarters of the country's former opposition party, Cambodia National Rescue Party (CNRP), in the capital Phnom Penh on Tuesday.
The presiding judge issued the order pending damages payments from CNRP leader Sam Rainsy to Prime Minister Hun Sen and another ruling party leader.
A municipal court found the CNRP leader guilty of defaming Hun Sen in December and sentenced him to pay $1 million (€800,000) in damages. The verdict was based on Rainsy's claim that the Cambodian premier had carried out bribery to break up the CNRP.
In a separate case, Rainsy was found guilty of defaming the president of the National Assembly, Heng Samrin, from the ruling Cambodian People's Party (CPP). Rainsy was ordered to pay damages of $62,500.
The CNRP headquarters was Rainsy's home before he moved to France in 2015 to avoid prosecution.
US curbs military support
The US administration issued a statement on Tuesday saying it was curbing military support and other aid programs for Cambodia amid concerns about recent democratic setbacks.
"Recent setbacks to democracy in Cambodia, however, caused us deep concern, including Senate elections on February 25 that failed to represent the genuine will of the Cambodian people," the White House said.
Cambodia is set to have a general election on July 29, but the CNRP is unable to participate. The Cambodian Supreme Court dissolved the party and banned 100 party members from holding political office in November after ruling it had tried to overthrow Sen's government.
But rights groups criticized the decision as part of a wider government crackdown against opposition parties and independent media. Kem Sokha, another CNRP leader, was also arrested in 2017 for allegedly plotting to overthrow the government with the US's backing.
Sokha and the US have denied the accusation.
amp/jm (AP, Reuters)