Neill, 38, is thought to have earned about $40 million during his career. He was declared bankrupt in January.

Dale Hernon, the head of creditor services at Begbies Traynor, an insolvency firm in London, said Neill was due to be interviewed in the coming weeks, News Corp reported.

"Mr Neill is due to be interviewed when he returns to the UK in the coming weeks, at which point the trustees will be able to obtain the background information required to determine the full scale of Mr Neill's debts," Mr Hernon said.

"At this early stage of proceedings, it is currently unclear to what extent any funds will be recovered."

Neill was heavily involved in the original bid for a western Sydney A-League club. As the primary investor with his business partner and manager at the time, Paddy Dominguez, Neill's bid - known then as Sydney Wanderers - ultimately failed and the FFA selected the Sydney Rovers as the more viable option. The Rovers bid also came to nothing before the FFA itself founded the Western Sydney Wanderers.

Neill's bid was thrown into controversy when Sydney bagman Michael McGurk was shot and killed, and his connections to Neill's bid became public.

At the time, Dominguez said there was no connection between the two, other than Neill asking McGurk to act as a middle man to secure further investment.

"There is no tie here. Mr McGurk was not a shareholder or an investor. He was somebody we did speak to because we knew he manages money and has very big clients. We put our proposal to him and he spoke to people, but in the end they weren't interested [in investing in the Sydney Wanderers]," Dominguez said. "Separate to that, Lucas Neill funds the A-League bid. There are no other investors, no one else. Lucas is the man behind the bid. He is the face of the bid and he is the one who provides the funds for the bid - no one else."

It is understood Neill and Dominguez are no longer working together in any professional capacity after splitting a few months ago.

The defender played much of his football in the English Premier League. He played for Millwall, Blackburn Rovers, West Ham, Everton and Watford.

In his heyday, he attracted interest from superclubs such as Liverpool, but ultimately chose to stay on as captain at West Ham.

He also played in the Middle East, Turkey and Japan.

He played four games for Sydney FC in the A-League.

Neill first played for the Socceroos in 1996. His last game for Australia was in 2013.

He was dropped ahead of the 2014 World Cup by coach Ange Postecoglou.