ALMOST half of Premier Ted Baillieu's cabinet ministers are using private staff to decide whether government documents should be released under freedom-of-information laws - and most of the time they refuse full access.

In a move that has undermined the Coalition's pledge for greater transparency, new figures show that over the past financial year, nine cabinet MPs - including the Premier - authorised their chief of staff or senior adviser to decide if information should be released publicly.

Ideally, decisions would be made by independent department officers rather than private staffers to avoid perceptions of political interference.

But according to the latest Freedom of Information annual report, Mr Baillieu continues to use his senior adviser, Don Coulson, as the gatekeeper of FOI requests relating to his private office. Attorney-General Robert Clark, Treasurer Kim Wells, Tourism Minister Louise Asher and Deputy Premier Peter Ryan all delegated decision making to chiefs of staff, as did ministers Martin Dixon, Mary Wooldridge, Michael O'Brien and Ryan Smith.

In opposition, Mr Baillieu repeatedly called the FOI system deficient, largely because ministers and senior department officers had ''inappropriate influence'' on FOI decisions.