Banks aware of unusual trading four years before 'London fix' investigation In all, 15 banks are reported to have been contacted in relation to the investigation, although, at this stage, no one has been formally accused of any wrongdoing. Conservative MP David Ruffley, a member of the Commons Treasury Committee, has now written to the Serious Fraud Office to ask what action it intends to take. "I think it's fairly clear that everyone in this country who has shares in pension funds, and that's most of us one way or the other, will have seen a fall in the value of those shares as a result of this," he told the BBC. And that's not a politician saying it - it is what a bank was telling its own customers in 2009.