As congressional Democrats prepare to start writing a budget resolution for the next fiscal year, leaders of the Senate Finance Committee are hoping that government investigators can help them zero in on tax cheats.

Finance Chairman Max Baucus , D-Mont., and Charles E. Grassley , R-Iowa, the panel’s top Republican, on Friday said the Government Accountability Office is sending investigators next week to the Cayman Islands to check out a five-story building listed as the address of thousands of U.S. and international companies.

The visit is part of an ongoing effort to clamp down on the use of offshore tax havens in an effort to collect revenue that currently escapes the reach of the IRS.

“Our hope in sending GAO investigators to the Caymans is to get some answers about whether business there indeed contributes to the U.S. tax gap, which totals more than $300 billion each year,” Baucus said. “The tax gap represents taxes legally owed but uncollected, and we know that some of the gap is the responsibility of entities breaking the law by funneling money to offshore locations at the expense of honest, hardworking Americans who pay their taxes.”

Grassley said, “We need to strike the right balance between allowing Americans to benefit from the global economy and policing the evasion of U.S. taxes. The Ugland House office building in the Cayman Islands has been the source of much debate on the Senate floor over the past few years. It’s good to have U.S. auditors and investigators with a neutral perspective try to find out what’s really going on there.”