Bank of England Governor Mark Carney has warned many finance workers are unaware of the standards of conduct expected in the wake of the Libor rigging scandals.

Mr Carney stressed there is a need for them to exceed that required by the letter of the law.

His comments came as the bank stepped up its regulatory scrutiny of senior City figures in the wake of scandals hitting the trillion-dollar markets for foreign exchange and interbank lending.

Earlier this month Mark Carney and Chancellor George Osborne announced longer jail terms for traders who break the law, but the governor said a broader shift towards more ethical financial market practices is needed.

Speaking at a conference in London, he said: "A lot of people in these markets didn't really know, and probably still do not know, what is expected of them because it hasn't been adequately defined in everyday language.

"There are Aristotelian ethics up here, and very black-letter regulation down here, and you can go round that in some cases but still be offside."