WA govt defends 'confidentiality' blackout

Western Australia's planning authority will be asked to reassess the extent to which it hides information about major public projects behind a wall of confidentiality claims.

In its annual operation plan, tabled in parliament in October, the Metropolitan Redevelopment Authority heavily redacted information including projected revenue, developer contributions, costs and profits in the name of "commercial-in-confidence".

Planning Minister John Day said on Monday the MRA withheld the figures because it did not want to flag expected revenue targets, jeopardising a return to taxpayers, but conceded that may need to be reviewed.

"I will ask the MRA to review the scope of how much is blacked out to see whether there can be some change next year but there is certainly no way we are going to make public, to the possible taxpayers' detriment, commercial information and forecasts," Mr Day told 6PR Radio.