Five KPMG LLP partners, including the head of its audit practice, were fired after the Big Four accounting firm improperly obtained information about which audits its regulator planned to inspect, the company said.

The company’s regulator, the Public Company Accounting Oversight Board, began investigating a leak discovered in February of its plans to inspect KPMG’s work. Among the fired KPMG employees was Scott Marcello, who was a partner and headed the audit practice, the company said.

An employee of the accounting board who leaked the information to KPMG left the PCAOB after the leak was reported to the regulator, which oversees firms that audit U.S.-traded public companies, according to the PCAOB.

The firm on Tuesday confirmed the role of its executives and their firings after being contacted by The Wall Street Journal. Mr. Marcello didn’t respond to requests for comment.

Also among those fired was David Middendorf, KPMG’s national managing partner for audit quality and professional practice, according to a person familiar with the matter. Mr. Middendorf couldn’t immediately be reached for comment. The identities of the other fired partners weren’t known Tuesday evening. The company said it also dismissed a sixth employee, whose identity and role could not be learned.