Travers Smith received more than £2m in fees for its role on an investigation into what Bank of England officials knew about manipulation of the foreign exchange market.

Travers was appointed in March along with One Essex Court's Lord Grabiner QC, to lead a review into the Bank's practices, in response to allegations that some Bank officials allowed the manipulation of foreign exchange (forex) rates by bankers in the City. The six banks involved received multi-million pound fines.

Travers was responsible for the inquiry's substantial data review exercise, employing a team of up to 12 lawyers extracting and applying search terms to 1.8 million documents and 87,000 telephone calls, for which it received £2.2m in fees.

The total cost of the inquiry was £2.9m excluding VAT, according to a letter from Anthony Habgood, chair of the Bank's governing body, to Andrew Tyrie, chair of the House of Commons' treasury committee.

The cost included a £401,000 payment to Lord Grabiner and a £106,000 payment to Adam Rushworth, a junior barrister at Lord Grabiner's Chambers who assisted him on the job.

Specialist law firm Huron Legal processed and hosted all of the electronic documents under consideration, providing technical assistance for searching them, for which it was paid £107,115.

Nexidia, which did the same for telephone calls, was paid £80,500 and Opus 2, which provided transcription services for the various interviews Lord Grabiner conducted with Bank and non-bank staff, received £14,000.

The findings of the report, which were released in November, eventually exonerated bank officials, stating that none had engaged in any unlawful or improper behaviour in the forex market between 2005 and 2013.