Carl Wulff, who worked at Wollongong council from 1985 until his resignation from the assistant general manager's position in 2000, stood down from his job with the Queensland city's council on December 13.

He also resigned from positions with five other companies connected to Ipswich City Council.

Queensland's Crime and Misconduct Commission is investigating the financial ties between Mr Wulff and consulting company Professional Consulting Group (PCG), a firm assisting the council with flood-recovery work.

The commission originally asked the council to investigate the complaint against Mr Wulff, but has since taken over the investigation itself.

The Courier Mail reported Mr Wulff had rented his apartment to PCG in Hamilton Harbour, in Brisbane, for $850 a week and that the council then reimbursed the firm $48,000 for rent paid for a year. Mr Wulff previously told the newspaper the company's decision to rent his property was not related to it securing the flood-recovery work.

The newspaper also reported the wife of a PCG consultant had taken a mortgage over the apartment last year as collateral to secure a debt to be repaid to her.

But Mr Wulff said he had declared it during and prior to the investigation.

Mr Wulff began as a division engineer at Wollongong City Council in 1985 and worked in a number of roles until becoming assistant general manager in 1993.

Announcing his resignation at the start of the new millennium, Mr Wulff told the Mercury he was especially proud of helping to introduce a state-of-the-art recycling facility to the city, called the Solid Waste to Energy Recycling Facility. The facility closed in 2004 following technical difficulties.

After leaving Wollongong, Mr Wulff took up a job as general manager of city services with Darebin City Council in Melbourne.

He had been chief executive at Ipswich City Council since 2006.