Former Ipswich mayor Paul Pisasale has been arrested and charged with extortion amid an investigation by the Crime and Corruption Commission (CCC).

Mr Pisasale was arrested by the CCC on Tuesday afternoon in Ipswich and was taken to the Brisbane police watch house where he was formally charged with extortion and two other offences.

He has been remanded in custody and is expected in the Brisbane Magistrates Court on Wednesday.

The CCC said the investigation was ongoing.

Prior to being charged, acting Ipswich Mayor Paul Tully said he and his colleagues were shocked by Mr Pisasale's arrest.

"As I understand it, these are strictly personal matters — have nothing to do with the Ipswich City Council," he said.

"It is a matter for Paul and his legal advisors and the Queensland judicial system.

"We had no warning that this could happen, but the city must go on and we're going to provide positive leadership into the future," Cr Tully said.

"Our sympathies do go out to Paul's family who are obviously very concerned at this difficult time.

"I think people will still remember Paul whatever happens as the person who put Ipswich on the map, did a lot of economic development for the city.

"As a council the city is in strong hands. Hopefully the city can move forward and Paul will have to address these issues the best he can."

Sorry, this video has expired Ipswich Mayor Paul Pisasale announces his resignation from the city's top job

Wearing a hospital gown and slippers, Mr Pisasale quit his long-standing post on June 6 at his local hospital, where he was being treated for multiple sclerosis.

His resignation came a day after the CCC and police searched his office, west of Brisbane, as part of an unfolding investigation.

At the time, police sources confirmed Mr Pisasale was stopped at Melbourne Airport last month with $50,000 cash, after a one-night trip on official business interstate.

Mr Pisasale was first elected to council in March 1991 and since 2004 he has had four terms as mayor.

In the 2016 election he was re-elected with more than 80 per cent of the vote.