Gibson Guitar is in trouble with another federal agency.

The Internal Revenue Service filed a lien against the legendary guitar manufacturer Monday for $445,994 in unpaid corporate and payroll taxes dating back to 2006.

The lien, filed with the Davidson County Register of Deeds, shows Gibson with unpaid 2006 payroll taxes totaling $3,350 and two years of corporate income taxes of $442,644 from 2007 and 2008.

It's the latest chapter in a string of troubles for the music instrument icon. In November 2009, agents from the U.S. Fish and Wildlife Service raided Gibson's Massman Road manufacturing center.

Sources told NashvillePost.com the Nashville-based guitar manufacturer was under investigation for violating the Lacey Act, a key piece of environmental law, for importing endangered species of rosewood from Madagascar.

Rosewood is widely used in the construction of guitars and sells for $5,000 per cubic meter, more than double the price of mahogany. The island nation off Africa's east coast is a key producer of the hardwood, the export of which has links to international criminal activity.

In a statement, the company said it was fully co-operating with the investigation and, to date, no charges have been filed.

More recently, Debtwire reported that Gibson's main lenders are pushing CEO Henry Juszkiewicz to improve his company's governance standards and that they're weighing tighter standards. Some also signaled they may at some point consider forcing a restructuring at Gibson.