British banks have been ordered to set aside more than £1bn over suspected rate manipulation in Singapore.
At least three UK-based global banks have been told to allocate the provision over the Singapore Interbank Offered Rate (Sibor).
The decision comes less than a year after the banking industry was rocked over rate manipulation in London-based Libor.
The Monetary Authority of Singapore (MAS) ordered Royal Bank of Scotland (RBS) to set aside £510m to £612m, while Barclays and Standard Chartered have been told to prepare a provision of between £200m to £300m each.
The money is being set aside to cover "deficiencies and risks" as part of the Singaporean review of activity between 2007 and 2011.
The money will be held at 0% interest rates for a year while the MAS considers how to improve controls on benchmark rates.
The MAS says 133 traders between these banks were found to have tried to influence these benchmarks.
The MAS says it will make rate-rigging a criminal offence.
Standard Chartered told Sky News: "We accept the findings of the MAS review."
In a statement, RBS added: "RBS has co-operated fully with MAS on its review of benchmark submissions and will comply with any required regulatory, capital and remedial measures."
Barclays declined to comment when approached by Sky News.