Caterpillar Inc. shares headed for the steepest decline in eight months as the biggest maker of machinery for mining and construction had its Illinois offices raided by U.S. tax and financial officials.

Searches were conducted on March 2 in Peoria, East Peoria and Morton by the Internal Revenue Service, the Federal Deposit Insurance Corp. and the Commerce Department, Sharon Paul, a spokeswoman for the U.S. attorney’s office for the Central District of Illinois, said by telephone.

Declining to give details on the nature of the raid, she said that in other cases the U.S. attorney’s office has dealt with the IRS’s Criminal Investigations unit and the Commerce Department’s Office of Export Enforcement. Caterpillar has a financial unit that lends to customers.

Caterpillar confirmed by email the presence of agents in some of its Peoria-area facilities, without elaborating. “Caterpillar is cooperating,” it said.

The stock fell 5.1% to $93.60 at 1:05 p.m. in New York, heading for the biggest decline since June.

The raids come as new CCEO Jim Umpleby shifts the global headquarters to Chicago to bolster the iconic U.S. machinery maker’s push in foreign markets. Last week, Oberhelman, who remains as chairman, participated in discussions on pro-growth policy with the administration of President Donald Trump.

Previous Subpoenas

Although it isn’t clear what the focus of the raids are, the company disclosed in an annual filing last month that it received a grand jury subpoena from the U.S. District Court for the Central District of Illinois on Jan. 8, 2015.

The subpoena requested documents relating to, among other things, financial information on U.S. and non-U.S. Caterpillar subsidiaries. That included undistributed profits of non-U.S. subsidiaries and the movement of cash among U.S. and non-U.S. subsidiaries, the company said.

The manufacturer said it got additional subpoenas relating to this investigation requesting more information on the purchase and resale of replacement parts by Caterpillar and non-U.S. Caterpillar subsidiaries and dividend distributions of certain non-U.S. Caterpillar subsidiaries. The company said in the filing that it believes this matter “will not have a material adverse effect on the company’s consolidated results of operations, financial position or liquidity.”

“I can confirm that our agents are on-site conducting official business,” said Justin Cole, spokesman for the IRS Criminal Investigation division. “I’m unable to give any more details.”

A spokesman for the FDIC declined to comment.

By Joe Deaux and Joe Richter