Dennis Kozlowski, via CBS News

Jailed Tyco International Ex-CEO Dennis Kozlowski filed court papers this week requesting he be freed from prison after serving four years, according to a Bloomberg News article.  He was sentenced up to 25 years.

The investigation into Kozlowski’s illicit activities was triggered by his art buying activities.

Kozlowski said “his right to present a defense was violated when a New York state trial judge denied his request to subpoena early statements of prosecution witnesses,” says Bloomberg.

In 2005 Kozlowski was convicted of grand larceny and securities fraud, among other charges.

He was charged with purchasing $14 million in impressionist artworks by Monet and Renoir using Tyco funds via a company loan program. He was also charged with not paying the 8.25 percent New York sales tax.

He wound up paying $3.2 million in back taxes on the artworks, plus $18 million in income taxes to avoid tax evasion charges, according to an earlier Bloomberg article.

Several of Kozlowski’s paintings were auctioned at Sotheby’s in 2006.