British accounting regulators have started an investigation into KPMG’s auditing of controversial defense company BAE Systems.

The company has for years been battling allegations that it paid bribes to secure arms deals around the world. Earlier this year it agreed on a settlement and substantial fines with prosecutors in the United States and the United Kingdom.

The probe covers KPMG’s audits of BAE in the decade up to 2007. The focus is on commissions paid by BAE to “subsidiaries, agents, and any connected companies.”

The regulator is also looking at any professional advice, consultancy, or tax work that KPMG provided in respect of commission payments and the “status, operation, or disclosability” of three offshore BAE subsidiaries.

BAE agreed to pay a $400 million fine to the Department of Justice earlier this year after admitting to "defrauding the United States" over the sale of fighter planes to Saudi Arabia and Eastern Europe. It also reached a £30 million ($48 million) settlement with the U.K.'s Serious Fraud Office (SFO) for "breaching its duty to keep accounting records."

The investigation is being carried out by the Accountancy and Actuarial Discipline Board (AADB), an independent body that disciplines accountants.

The board has the power to file a disciplinary complaint against an accountancy firm and individuals, and it can impose an unlimited fine and withdraw a practicing certificate or license.

KPMG, which is still BAE’s auditor, said it did not believe there had been any misconduct.