A COLOURFUL Queensland mayor who suddenly resigned after 13 years on Tuesday morning was reportedly caught at an airport with $50,000 cash in his carry-on luggage last month.

Ipswich mayor Paul Pisasale fronted media to resign on Tuesday morning but claimed failing health, not a corruption probe, was behind his shock decision to stand down.

The resignation came amid a probe into Cr Pisasale by Queensland’s corruption watchdog and the Australian Federal Police that saw his council office and home raided and computers seized on Monday.

Later on Tuesday, it emerged that Mr Pisasale was stopped by police at Melbourne airport on May 13, where he was found to have $50,000 cash in his carry-on luggage.

BREAKING: AFP detained & quest Ipswich Mayor Paul Pisasale over $50,000 cash in his carry-on at Melbourne Airport, May 13 @7NewsQueensland — Paula Doneman (@PaulaD7news) June 6, 2017

The Queensland Crime and Corruption Commission is leading an investigation into the now former mayor and confirmed it had raided his office.

But Mr Pisasale declined to comment on the investigation when he faced the media at Ipswich’s St Andrew’s Hospital on Tuesday morning.

He was unusually subdued - and sporting a white dressing gown - when he formally announced his resignation and cited his 30 year battle with multiple sclerosis as the reason behind his decision.

The now former mayor declined to answer questions on the CCC investigation, which the Courier-Mail has reported also involves a developer.

But Cr Pisasale, now just Mr Pisasale, maintained his resignation was fuelled by his ongoing health battles.

His deputy, Cr Paul Tully, will step into the mayoral robes for three months until a by-election can be held to elect his replacement.

Mr Pisasale is a hugely popular figure in Ipswich, having served on the council for more than 25 years.

He has served as mayor since 2004.

“I have been investigated by the CCC over the years and I have co-operated wholeheartedly,” he said.

“I’ll wait and see what that’s (the CCC announcement) is about.”

Mr Pisasale has been subjected to a number of CCC probes during his time as mayor but has always been cleared of wrongdoing.

He said he had been discussing resigning for the past four weeks but had an MS attack in the past 24 hours that nailed the decision for him.

“I have been a champion for MS for the past 30 years, it is a tough disease and I have been able to set an example,” he said.

“But when MS starts impacting your ability, I have had an MS attack, it has forced (my resignation).

Mr Pisasale, despite being subject to a number of crime investigations in his time as Ipswich’s mayor, is a much-loved figure in the city.

He regained the city’s mayoralty at last year’s local government elections with a massive 83 per cent of the primary vote.

The CCC is expected to release a statement regarding the investigation this afternoon.