In the past, he has been open about the importance of the support he has had from Mr Burnham’s Manchester council officials.
Money from GMHILF has “enabled us to do a lot more, quicker, than going out into the open market [for funding]”, he has said.
Speaking at a property conference in Cannes, France, this year he said: “We shouldn’t underestimate the strength of Manchester and how unique an environment we have.
“It is absolutely special and shining light in the UK in terms of that stability, delivery and that fundamental demand.”
Officials have defended the support for Renaker.
Eamonn Boylan, the GMCA chief executive, said in an interview earlier this year: “It is not the ‘Renaker show’ by any stretch of the imagination. We have not turned down a single viable scheme.”
Gill Boyle, a chartered town planner and regeneration specialist, said: “It is not clear how these loans were assessed against other potential projects throughout Manchester or projects that included housing for sale and not primarily rented flats.”
Ms Boyle added: “When public funding is used to assist in a regeneration property scheme, I would expect to see a rigorous process for assessing whether the funding is justified.
“The larger the funding, the more rigorous the process should be. This should include its value for money, risk analysis and assessment of outcomes and output.”
A spokesman for GMCA said: “We are aware of a claim submitted to the Competition Appeals Tribunal regarding the Greater Manchester Housing Investment Loans Fund.
“The GMCA has been delivering these investment loans to a range of developers for a number of years and we are confident in our processes.”
Mr Whitaker was contacted for comment and is not accused of any wrongdoing.
A Weis Group spokesman said last night: “The housing loans fund was set up with the promise of delivering for the people of Manchester but has mainly been funnelled to one builder of luxury flats in Manchester City centre.”