A Solomon Islands' judge has thrown out evidence in a murder trial because investigating Australian Federal Police forgot basic procedures.
High Court judge David Cameron found there were deficiencies of process by investigating police in taking two murder suspects' statements.
Murder suspects William Hence and Geddily Isa claimed the police tricked them into giving interviews in the ongoing case of Brother Nathaniel Sado, who was killed in 2003.
Judge Cameron ruled in their favour to have the evidence omitted, citing deficiencies of process and in Hence's case not being properly advised as to his rights.
Solomon's Police Commissioner Peter Marshall told AAP the omission of the evidence was not an embarrassment.
A verdict in the Brother Sado murder trial is expected next month.
Australian Federal Police and New Zealand officers are part of the Participating Police Force or PPF and mentor and assist local police.