Italy's economic development minister has resigned amid allegations that she passed along confidential information to her boyfriend that helped his business interests.

Federica Guidi announced her resignation Thursday in a letter to Premier Matteo Renzi that was posted on the ministry's website. Guidi denied wrongdoing but said she was resigning for "reasons of political opportunity."

Guidi's companion, Gianluca Gemelli, operates two companies in the oil sector and is among 60 people being investigated regarding the management of liquid waste produced by an oil field in southern Italy. On Thursday, six people were put under house arrest, including five employees of the Eni oil company.

Wiretaps published by Italian media indicated that Guidi had told Gemelli about an amendment to a law not yet public that would benefit his business.