A U.S. committee handed a $60 million fine to the country's third-largest wireless network operator T-Mobile for its failure to prevent and report unauthorized access to sensitive data.

The penalty, which represents the heftiest fine ever imposed by the Committee on Foreign Investment in the United States, is tied to violations of a mitigation agreement T-Mobile entered into with the panel when it bought Sprint Corp for $23 billion in 2020, the officials said.

The penalty imposed by the Committee on Foreign Investment in the U.S. (CFIUS) is tied to violations of a mitigation agreement that German-owned T-Mobile inked with the panel as part of its $23 billion acquisition of U.S.-based Sprint Corp in 2020.

T-Mobile did not immediately respond to a request for comment.

"The $60 million penalty announcement highlights the committee's commitment to ramping up CFIUS enforcement by holding companies accountable when they fail to comply with their obligations," one of the officials said, adding that transparency around enforcement actions incentivizes other companies to comply with their obligations.

The size of the fine, and CFIUS's unprecedented decision to make it public, show the committee is serious about taking a more muscular approach to enforcement as it seeks to deter future violations.