Opposition leader Sam Rainsy is expected to travel to Beijing this week to meet former king Norodom Sihanouk.
Royal Palace officials said Sihanouk, who is in Beijing for medical care, will fix a meeting for Tuesday, having already met Prime Minister Hun Sen several weeks ago.
No detailed information on the meeting was available, and a Royal Palace official declined comment.
Sam Rainsy told VOA Khmer his audience with the former monarch, who abdicated in 2004, was private.
Opposition officials said recent political and economic developments could be on the agenda.
The Sam Rainsy Party won 26 of 123 National Assembly seats in July's elections, which the party labeled fraudulent, a claim Hun Sen's ruling Cambodian People's Party, which won 90 seats, denies.