Samoa's police commissioner, Fuiavalili Egon Keil, has told an inquiry he could not recall issuing instructions to reopen an investigation into Mauga Precious Chang.
A commission is investigating alleged evidence tampering by an assistant police commissioner and a superintendent.
The evidence related to traffic charges against Ms Chang who was then the director of the National Prosecution Office.
The inquiry chairman, former Supreme Court judge Lesatele Rapi Va'ai, questioned Fuiavailili about the handling of the case against Ms Chang.
When asked by Lesatele if he had instructed the now suspended assistant police commissioner Samoa Mulinu'u to reinvestigate Ms Chang's case, Fuiavaili said he could not remember.
Our correspondent in Samoa, Autagavaia Tipi Autagavaia, said there was evidence confirming he did.
"There is evidence before the Commission of Inquiry that he instructed for another investigation of the traffic incident against the former director of the NPO but his answer was he didn't recall. It's up to the Commission of Inquiry to determine the evidence before them now."