* Businessman, former bank chairman deny wrongdoing
* Some 25 people charged over bad loans at state bank
* Bank wound down after being hammered in debt crisis
By Renee Maltezou
ATHENS, Jan 9 (Reuters) - A Greek businessman and two former Hellenic Postbank executives have been arrested on charges of money laundering and fraud against the state, court and police officials said on Thursday.
Greek prosecutors are looking into a series of loans which the state bank issued from 2007-2012 and which resulted into 500 million euros of losses for the bank.
Hellenic Postbank, also called TT, was wound down last year after being hammered in Greece's debt crisis, with its healthy assets sold to Greek lender Eurobank.
A total of 25 people have been charged over the bad loans at Hellenic Postbank, court officials said, including Greek businessman Lavrentis Lavrentiadis, who is already in custody pending trial over another banking case in which he denies wrongdoing.
Greek businessman Dimitris Kontominas, 75, who owns a Greek TV channel, was arrested on Wednesday while in hospital, the court and police officials said on condition of anonymity. It was not immediately clear why he was hospitalised.
Police have yet to formally comment other than to say three people have been arrested.
Kontominas has denied any wrongdoing and was expected to appear before a judge on Tuesday to respond to the charges.
"There is not even a trace of illegality in my business activity," Kontominas said, according to state agency ANA.
Two former TT executives were also arrested on Wednesday and were expected to appear before a prosecutor on Thursday. Prosecutors have also issued arrest warrants for four others, including TT's former chairman Angelos Filippidis.
Filippidis told Greek Skai radio that he was on a business trip that he would cut short to appear before the prosecutor in Athens. He has denied the accusations.
"I'll explain each and every loan," he said. "All of the loans ... were issued correctly and if I could turn back time, I would issue them again."
Greece's financial crisis has triggered public anger against a political and business elite widely viewed as privileged and corrupt, prompting prosecutors to step up corruption investigations.
Authorities wound down TT in January 2013, after efforts to sell it failed. Greece's bank rescue fund HFSF pumped about 4.5 billion euros into the bank, stripped it of it bad loans and sold the entity to Eurobank in July as part of a wave of consolidation in the country's battered banking sector. (Editing by Jeremy Gaunt)