Wenham Major, a Birmingham-based accountancy firm, has launched an internal investigation following the discovery of 'financial irregularities' in one of its subsidiary businesses.

Ammar Azam, a director who jointly owns the firm with chairman John Joyce, began the review of Wenham Major Private Client Limited, which operates as a tax planning business for high-net-worth individuals, after he uncovered discrepancies in the business.

John Joyce, who is in hospital and was not immediately contactable, 'is currently the primary subject of the company’s investigations'. A statement from Wenham Major Global Capital Partners said that as a result of preliminary findings, the firm plans 'to issue proceedings against John Joyce. John Joyce’s staff are cooperating fully,' the firm said in a statement.

The statement added that the general accounting practice, Wenham Major Limited, run by Azam, 'continues to operate in a professional manner and is not the subject of any suspicion'.

Wenham Major shot into Accountancy Age's Top 50 league table in 2006 and last year jumped 20 places to reach 23rd position in the annual table of accountancy firms' fee income.

In 2007 the firm reported £10.5m in tax fee income compared to £1.9m for the general accounting practice, growing at a rate of 92% compared to the average growth rate for the Top 50 of 13%.