Prominent Solomon Islands lawyer, Andrew Nori, says foreign police operating separately from local police command are operating contrary to the country's constitution.
Mr Nori, who's facing criminal charges after a joint police investigation, is challenging the validity of parts of the Facilitation of International Assistance Act that allowed the Regional Assistance Mission into the country.
Mr Nori is seeking a High Court ruling that the Act is unconstitutional and that, therefore, the Participating Police Force cannot continue in its present form.
"Now here we are having a foreign force in Solomon Islands carrying out police operations which is not subjected to the management, to the control and discipline of the Commissioner of Police who has the constitutional authority estabished by the Solomon Islands Constitution, to command and look after the police force in Solomon Islands."
Andrew Nori's case follows a separate challenge alleging that police working under RAMSI breached the constitution in a series of incidents in December.
The PPF head, Sandi Peisley, has until next Wednesday to decide whether to claim immunity.
Ramsi says it's confident of its position in Solomon Islands.