Andrew Coster has apologised, saying he should've done better when he was Police Commissioner

He's resigned as Social Investment Agency chief executive, effective today.

It follows an IPCA report highlighting failures in how some senior Police dealt with allegations against then-Deputy Commissioner, Jevon McSkimming.

Coster's statement says it's clear Police handling of the whole matter was lacking, and he was ultimately responsible.

He's apologised to the woman at the centre of the case - and apologised to all Police.

Public Service Commissioner Sir Brian Roche says he respects Coster's decision, which was the right thing to do.