Caterpillar (CAT) - Get Report on Wednesday said the federal probe of the company currently underway goes beyond a previously reported tax issue and also deals with the heavy equipment maker's overseas business dealings.

Amy Campbell, Caterpillar's director of investor relations, revealed the news at the Bank of America Merrill Lynch Global Industrials and EU Autos Conference on Wednesday.

Responding to a question from Bank of America Merrill Lynch analyst Ross Gilardi about the scope of the investigation, Campbell replied, "I don't have any speculation on any type of financial numbers, but the search warrant was broader than just the matters related around the IRS issue, so it included export filings among other things. And like I said, we're still trying to gain an understanding of the complete picture of why the authorities came in the way they did."

Federal agents raided Caterpillar's corporate headquarters on March 2. At the time the company said that the warrant was focused on collecting documents and electronic information and was most likely connected to an IRS investigation of parts transactions carried out by its Swiss affiliate.

Caterpillar has said in Securities and Exchange Commission filings that the IRS has proposed a $2 billion charge for back taxes and penalties. The New York Times reported that the government-commissioned report concluded that Caterpillar deliberately broke U.S. tax law and financial reporting rules when it failed to pay taxes on earnings from the Swiss affiliate.

No charges have been filed against Caterpillar.