Libor is not the first price-manipulation affair in banking but it is one of the most serious, recalling the Treasury bond scandal at Salomon Brothers in 1991 that imperilled Salomon, now a part of Citigroup. Its chief executive, John Gutfreund had to resign after Paul Mozer, a bond trader, submitted false bids in the T-bill market.

A similar scandal erupted in the US natural gas market in 2002 when the CFTC fined a number of companies. One of them was found to have kept a spreadsheet of prices labelled “bogus”, as the real ones. In a recent speech Scott O’Malia, a CFTC commissioner recalled the energy sector as “the wild wild west” in which “no one quite knew who was the sheriff and who was the outlaw.”

More recently questions have been raised about the market for dollar swaps – derivatives linked to government bond yields – with prices set every day at 11am in New York. As in the case of Libor, the pricing process is dominated by a handful of banks.