Ex-Anglo Irish Bank chief executive David Drumm borrowed from his former employers to invest in a movie starring Colin Farrell, but never paid the money back.
Mr Drumm (44) bought shares in a production company behind the film 'Triage', in which the Dublin-born Hollywood actor starred as a warzone photojournalist.
The movie caused controversy after Farrell lost weight to play the role.
Documents seen by the Irish Independent reveal Mr Drumm, who is filing for bankruptcy with liabilities of €10.26m, invested €31,750 in the company behind the movie, Darkroom Productions Ltd, in 2008.
The investment was part-funded through a loan of €8,414 from Anglo, which was due to be repaid nine months later.
However, despite securing a significant tax break because of the investment, Mr Drumm never paid the money back.
The banker quit Anglo and fled to the US two years ago after it emerged the bank's chairman Sean FitzPatrick had been hiding loans of up to €100m from shareholders.
Mr Drumm is now living in a $2m (€1.4m) home on the outskirts of Boston and has so far refused to return home to face garda questioning over major irregularities at Anglo.
A spokesman for Darkroom Productions said the company had been unaware that Mr Drumm was an investor and said that he had no other connection to the film project.
"Hundreds of people can invest in a film. We generally don't know who the people are. They primarily do so to get a tax break," the spokesman said.
In buying shares in the company, Mr Drumm benefitted from tax relief which aims to promote the Irish film industry by encouraging investment.
In the past, Anglo was involved in gathering together groups of business people to help bankroll film projects, with investors putting up sums of up to €50,000 each.
'Triage', with a reported budget of €10m, was not a major success. Although it was shown at film festivals, it has not been distributed widely.
Details of Mr Drumm's involvement in the financing of the movie emerged in legal correspondence relating to bankruptcy proceedings in the US.
The bank is Mr Drumm's largest creditor, claiming it is owed €8.5m.
Most of the debt relates to loans to Mr Drumm so he could buy shares in the bank. These shares are now worthless after Anglo was nationalised.
The bank has questioned the accuracy of financial information provided by Mr Drumm to the US courts as part of his bankruptcy petition and has asked a judge to allow it to quiz him on his affairs under oath.
Mr Drumm has already stated under oath that the information, which lists assets worth €9.99m, is "true and complete".
But Anglo is seeking proof, including records on his assets and property dealings.
However, the bank's application received a major blow yesterday when it was opposed by interim bankruptcy trustee Kathleen Dwyer, who is administering Mr Drumm's estate.
In a court filing last night, Ms Dwyer argued Anglo's application to question Mr Drumm impinged on her role.
A judge is set to rule on the matter next month.