Olswang's general counsel Stephen Hermer has been asked for further details on the firm's involvement in the sale of BHS, including how much the firm's fees for the transaction were.

Chair of the Work and Pensions Select Committee, Labour MP Frank Field, has written to Hermer to request further evidence following the latter's appearance in front of the committee last week (25 May) as part of MPs' investigation into the sale.

Field has asked Hermer how much Olswang charged Retail Acquisitions Limited (RAL) in relation to its purchase of BHS and how much in total it has billed RAL on this and other matters.

Olswang advised RAL on its acquisition of BHS for £1 from UK retail billionaire Sir Philip Green's Arcadia group in March last year.

The high street stalwart went on to enter administration in April this year.

Olswang London corporate partner and head of the firm's leisure and retail practice, David Roberts, led its team and had been expected to appear in front of the committee last week. But Hermer appeared as his replacement.

Field's letter to Hermer, dated 31 May, also asked how much of the fees charged by Olswang were contingent on successful completion of the sale.

He also requested information on the due diligence process undertaken by Olswang into the source of any monies paid to it in fees, specifying: "How many steps back does Olswang look to trace the ultimate source of such monies?"

Field also said that Arcadia's finance director Paul Budge had given evidence to the committee, stating that RAL had put £35m into an escrow account with Olswang. Field asked Hermer what steps Olswang had carried out to find out how this sum had been raised.

Field has given Hermer until 6 June to respond.

Last week, the veteran Labour MP criticised the use of client privilege by partners questioned on the sale and subsequent collapse of BHS.

Prior to the committee meeting that Hermer attended. Field told Legal Week: "I just think it's too easy to claim privilege. It's just laziness and a cover up."

He added: "Fee income seems to muddle people's memories."