The Royal Bank of Scotland (RBS) has defended claims that its instruction of Clifford Chance (CC) to lead an independent review into the bank's lending activities amounts to a conflict of interest.

On Monday (25 November), RBS confirmed it had instructed CC to investigate claims the bank conducted a "systematic" effort to profit on the back of small business customers in financial distress.

Several commentators, including the journalist Ian Fraser, have taken to Twitter to suggest CC cannot offer independent advice to the bank, given the firm's appointment to the bank's legal panel last year.

Fraser cited evidence that the magic circle firm was separately acting for the bank in on-going litigation.

An RBS spokeswoman said the partners involved in the investigation – understood to include partners Carlos Conceicao and Kelwin Nicholls – have had no previous dealings with the bank's global restructuring group (GRG), the part of the bank which is alleged to have mistreated business customers.

"Clifford Chance will conduct the review on an independent basis, it will be led by a regulatory partner within the firm and with a team that has had no previous dealings with GRG matters," said RBS in a statement.

"Clifford Chance will review the key findings of the Tomlinson Report, review the relevant policies and practices within RBS through relevant interviews and targeted sample and data analysis, advise RBS on whether the allegations appear to have substance and make recommendations about steps, if any, RBS should implement as a result."

The bank also confirmed the final report would be delivered by 31 January 2014, and "will recommend appropriate thematic responses based on its conclusions".

CC's work will be overseen by the bank's head of conduct and regulatory affairs Jon Pain.

The move is not the first time members of CC's regulatory team have been put into silos on high-profile work. Last year, the firm put a so-called "Chinese Wall" in place to allow it to advise both RBS and Barclays on matters resulting from the Libor scandal.