Democratic Rep. Jim Cooper and Republican Rep. Marsha Blackburn said at a press conference in a Nashville recording studio that the bill would protect people from charges for unknowingly possessing illegally imported wood, and would require the federal government to establish a database of forbidden wood sources.

The measure would also exempt any wood imported before 2008 changes to the federal Lacey Act, which bans wood products illegally exported from foreign countries.

“For these old instruments before 2008, you can’t uncut a tree,” Cooper said. “This was already done. It’s spilled milk.”

Officials with the U.S. Justice Department and the Interior Department in a letter to members of Congress last month said it is not a crime to “unknowingly possess” such instruments, and that prosecutors would target only “those who are removing protected species from the wild and making a profit by trafficking in them.”

Blackburn said the bill would make that approach the law.

“We don’t want individuals to have to depend on the language of that letter,” she said.

Rep. Mary Bono Mack, R-Calif., is expected to co-sponsor the bill.

Cooper said changes to the law wouldn’t affect the case involving Nashville-based Gibson Guitar.

Agents last month raided Gibson factories and offices in Nashville and Memphis after seizing what they deemed illegal ebony shipped to the guitar maker from India. Similar raids were conducted in 2009 over wood from Madagascar.

Gibson and its wood importer Luthiers Mercantile International filed arguments in federal court this week opposing the government’s efforts to indefinitely halt the legal dispute over the seized wood while pursuing what prosecutors call a related criminal investigation.

Gibson in its Tuesday filing decried what it called the government’s “delay tactics” in a case that it said has “reached a legal dead end.”

The two-year investigation has “created an unjustified cloud of suspicion over Gibson,” with little result other than to hamper the company’s ability to make guitars, according to the filing.

Windsor, Calif.-based Luthiers Mercantile argued in a separate filing that the criminal investigation is related to the wood imported from Madagascar in 2009, and not this year’s import of ebony from India.

“The government is using an indefensible argument to seize fingerboards destined for Gibson and then trying to indefinitely hold those fingerboards under cover of a never-ending ‘related criminal investigation,’“ according to the filing.

There are ties in both cases to German importer Theodor Nagel GmbH. Federal investigators say Gibson sought to acquire the wood from Madagascar through Nagel in 2009. Luthiers Mercantile’s website indicates that both it and Nagel share the same owner.

Court documents filed in Hamburg, Germany, indicate that Nagel entered into bankruptcy proceedings there last month. The two managers of Nagel listed in the German bankruptcy notice, Andreas Krauth and Dieter Krauth, are also listed as directors of Luthiers Mercantile in the company’s corporate filings in California.

Gibson has denied any wrongdoing, and Luthiers Mercantile in its filing suggests the guitar maker is being singled out unfairly.

“Shipments of such fingerboards continue to arrive in this country on a regular basis, and have for years,” the company argued in the document. “Apparently, if those fingerboards are destined for Gibson, they are seized; if they are destined for another manufacturer, they are not.”

The raids have had political repercussions. Gibson has drawn the support of Republicans and tea party groups decrying the raids as examples of overzealous regulation and a threat to American jobs.