David Bailey, head of market infrastructure and policy at the Financial Conduct Authority, has said that he has seen "no clear evidence" of collusion between banks in the gold fix and gave no indication that the UK investigation into currencies trading is set to wrap up soon.

Speaking to a committee of UK lawmakers, Bailey repeatedly refused to be drawn on which benchmarks in the financial system were particularly vulnerable to efforts at manipulation, but he added that it was "possible" for all of them. "The important thing is that the process by which they are fixed is robust," he said.