The criminal investigation into former traders at Royal Bank of Scotland over the Libor scandal is set to drag on well into next year, dashing hopes that the government-controlled lender can swiftly put past scandals behind it.

The UK's Serious Fraud Office launched a criminal probe over two years ago into whether the key London interbank offered rate benchmark was manipulated. It has recently written to the financial regulator asking it to postpone publishing civil findings against at least two former RBS traders, according to people familiar with the situation.

Legal experts said this indicated that the SFO was still weighing whether to bring criminal charges against the individuals.

The Financial Conduct Authority – which has its own probe into alleged Libor-rigging – wanted to fine at least one of the traders £1 million. – (Copyright the Financial Times Ltd 2014)