Berkshire Hathaway Inc. thinks it was duped.

Billionaire Warren Buffett’s company took a $377 million charge after investing hundreds of millions in tax-equity investment funds tied to a company that federal authorities say engaged in fraud, according to Berkshire’s first-quarter regulatory filing. The investments were tied to DC Solar, Debbie Bosanek, Buffett’s assistant, said Wednesday in response to Bloomberg’s questions about the expense. That’s the mobile solar generator company that federal authorities have alleged ran a fraudulent scheme involving tax benefits.

“In December 2018 and during the first quarter of 2019, we learned of allegations by federal authorities of fraudulent income conduct by the sponsor of these funds,” Berkshire said Saturday in the filing, without naming the sponsor. “As a result of our investigation into these allegations, we now believe that it is more likely than not that the income tax benefits that we recognized are not valid.”

Companies including Progressive Corp. and East West Bancorp Inc. also say they’ve been hurt by tax-related investments involving DC Solar, which allegedly promoted its ability to provide “very favorable tax consequences.” Law-enforcement officials searched a business tied to the case in December and alleged a “Ponzi-type investment fraud scheme,” according to court documents.

Read more: ‘Ponzi-like’ solar scheme risks liability for East West

For Berkshire, the $340 million it put in the tax-equity investment funds are relatively small compared with its $190 billion stock portfolio at the end of the first quarter. In renewable-energy tax-equity deals, investors including banks and insurers passively invest in clean-power projects in exchange for using federal tax credits that offset their own tax liabilities.

This story was provided by Bloomberg News.