The report said that any fine would be in addition to a penalty that the Justice Department is to announce when it resolves an investigation of Barclays and four other banks for manipulating currency benchmarks, the news service said.

The report said the scale of the fine is not clear; talks are continuing over the matter.

A spokesperson for Barclays and a spokesperson for the DoJ declined to comment, the report said.

The report said that Barclays would be the second bank to be penalised by the DoJ for breaking earlier vows of good behaviour as prosecutors pursue settlements against five firms over allegations they rigged currency trades.