Lawyers for Sam Rainsy have said the "acting president" of the Supreme Court-dissolved Cambodia National Rescue Party (CNRP) was looking forwarded to "having the relevant facts examined by an independent French court".

The statement comes after separate lawsuits were filed by Prime Minister Hun Sen and his son-in-law Dy Vichea after Rainsy claimed the prime minister was responsible for the death of Vichea's father.

“Under French law, the truth is a defence to defamation, and Sam Rainsy intends to demonstrate the truth of his public statement,” the lawyers said on Friday.

CNRP co-founder Rainsy has repeatedly claimed that Hun Sen was behind the death of former National Police chief Hok Lundy in helicopter crash in 2008.