A typed version was provided, but lawyers working for the SFO asked to see the original. It then emerged that the document had been destroyed.

It is understood that the SFO spoke to a “source” about the meeting and concluded that the electronic record that was on file was sufficient.

However, its disappearance will raise questions about the involvement of Labour ministers and civil servants in discussing the setting of the Libor.

Yesterday, Parliament was under pressure to launch an inquiry into allegations that the Bank of England and the previous Labour government may have been involved in manipulation of the rate.

The BBC’s Panorama said it had uncovered a 2008 recording of a conversation between a senior Barclays manager and its Libor submitter that suggests the Bank of England was exerting pressure to lower the rate.