IVOR Callely was questioned through the night after waiving his right to take an eight-hour break while in garda custody.
The former junior government minister opted to continue to be questioned through the night on allegations of producing false invoices to support his mobile phone expenses and was then set free at midday.
As he emerged from custody at Irishtown garda station on the southside of Dublin and walked into a bank of flashing cameras, his two solicitors issued a three-line statement stressing his innocence.
Unwilling to speak, he looked sheepish with an awkward smile as he was bombarded with questions.
Despite his all-night session, he appeared fresh and neatly turned out in a dark suit, an impeccable white shirt and brightly striped tie -- ever the politician, determined to shine in the darkest of hours.
"Mr Callely has been detained under section 4 of the Criminal Justice Act, which gives the Garda Siochana the power to investigate complaints," solicitor Noel O'Hanrahan read from a sheet of paper.
"Mr Callely has now been released. Mr Callely is completely and totally innocent of any wrongdoing," he added.
The 53-year-old former Dail deputy and senator was then quickly ushered away.
He had been arrested at midday on Wednesday as detectives from the garda national fraud bureau swooped on his home at St Lawrence's Road in Clontarf and his former constituency office on the Howth Road.
Officers later searched his holiday home at Kilcrohane, near Bantry, in west Cork.
Under the terms of his detention under section 4 of the Criminal Justice Act, he had the right to seek a suspension of questioning at midnight to allow him to take a rest.
But he chose to press on with the interview throughout the night, stopping only for his statutory breaks to catch his breath.
His arrest came in the final phase of the fraud bureau inquiry into allegations that he issued four invoices to support his claim for the purchase of mobile phones in his Oireachtas expenses, although the company listed on the invoices had ceased trading several years earlier.
Gardai will now put the finishing touches to a file they have prepared for the Director of Public Prosecutions, who will determine if Mr Callely should face criminal charges.
After his release yesterday, he walked calmly in silence from Irishtown station, climbed into the front seat of a silver Toyota car and travelled home to await the decision of the DPP.