UPDATED 11.22am: Ratepayers in west Auckland are welcoming an investigation into Auckland Council's involvement in a billion dollar new town centre at Westgate.

The Auditor-General is investigating a public-private partnership, which is costing ratepayers about $200 million.

The project was established by the former Waitakere City Council.

Massey & Birdwood Settlers Association Secretary John Riddell says the investigation should be welcomed by ratepayers and residents.

"It'll clear the air one way or the other as to what's been going on and possibly lead to either better developments and better controls on those developments and money being spent."

The council received an independent report in 2012 into allegations raised by councillor Chris Fletcher.

Talking Auckland blogger Ben Ross says the report was never made public and is calling on the council to release it now.

"We're looking at public money being sunk into a private project. We'd like to know what the allegations were and what the result was."

Ross says the council needs to release the report, and explain why it's taken so long.

"Why was the report never released and what's changed in three years to spark the Auditor General now to take a look."