Queensland government auditors have discovered a secretive development arm of the Ipswich City Council, having used up to $83 million of ratepayer dollars for property development deals.

Reports also revealed the company donated $10,000 to a school attended by children of three company directors.

Most shockingly, ICP, one of the council-owned companies examined, was set up for a $150 million facelift to the Ipswich city centre which has yet to come to fruition.