Joe McCarthy was arrested last month on suspicion of fraud, corruption, misconduct in a public office and money laundering after it emerged he had spent £80,000 on his corporate credit card.
Now it has emerged other payments he received are being investigated as part of a long-running investigation into allegations of corruption and other offences at Cleveland Police and the police authority. The payments all received formal approval from the police authority but it is understood the investigation is looking at whether there was any impropriety in the process.
Loyalty payments to Mr McCarthy for remaining as police authority chief executive began in 2008-09 when he received his first £25,000 bonus.
They continued until he was made redundant in June 2010 and further bonus loyalty payments, which would have been paid had he remained in post, were subsequently included as part of the total £362,000 pay-off package.
On leaving Cleveland Police Authority, Mr McCarthy became managing director of Reliance Police Support Services which had agreed a multi-million pound contract to provide custody services to Cleveland Police. He is understood to have left Reliance at the end of last year.
According to reports, when Mr McCarthy became the authority's chief executive in 2003, his basic salary was £79,275. In his first year of employment, the only extra payments he received were £907 essential car user allowance and £139 in expenses. By the time he left in 2010, his basic pay had increased to £113,000 but in the two years before his departure Mr McCarthy received total payments of just under £190,000 (2008-09) and just over £188,000 (2009-10).
As well as the annual loyalty payment, the chief executive had negotiated performance-related pay bonuses and an annual £8,000 car allowance.
In contrast, his replacement and the current chief executive, Stuart Pudney, receives a basic salary of £90,000 and no bonuses.
When the scale of the pay-off first became public knowledge last year, Cleveland Police Authority was subjected to criticism, with the Redcar MP Ian Swales saying taxpayers would be "horrified" at the amount. At the time, the police authority acknowledged the payment was "huge".
The police authority now says it cannot comment further on the pay-off and loyalty bonuses or how they were arrived at and agreed because of the ongoing police inquiry.
Mr McCarthy has not responded to attempts to contact him for comment.
Spending on Mr McCarthy's corporate credit card in the four years to his departure included more than £8,000 spent in restaurants and pubs.
Individual restaurant bills above £500 were settled on the card, which was also used to pay more than £1,500 to a company specialising in luxurious car audio systems.
More than £16,000 went on hotels, with a highest single payment of more than £750 at a hotel in Leeds. A further £9,000 went on flights.
So far seven other people have been arrested as part of the investigation.