Hale and Dorr, which reported turnover of $297m (£185.2m) in 2001, has launched an astonishing lawsuit against a former secretary, demanding the repayment of £750.

The Lawyer can reveal that the Oxford office of the firm, formerly known as Brobeck Hale and Dorr, has served papers on a former employee after she was mistakenly overpaid.

According to sources, the former employee left the firm in December after a period of sick leave. On leaving the then Brobeck Hale and Dorr, she signed a compromise agreement which means an employee must concur with the terms of their departure. The result of the agreement is that no legal action can be brought against the employer after the employee has left. Usually the agreement does not cover legal proceedings being brought against an employee, which in this case is for the minute sum of £750.

The firm recently changed its name to Hale and Dorr after Brobeck Phleger & Harrison, its partner in the European joint venture, which spans Oxford, London and Munich, collapsed last month.

The claim for £750 is understood to have been signed personally by Joe Pillman, the new partner-in-charge of Hale and Dorr's European offices. Pillman became the lead partner after Tom Kellerman unexpectedly stepped down.

Hale and Dorr did not return calls for comment.