One of the most controversial practices in the $5.1tn-a-day currency markets is in for further scrutiny, highlighting the challenge of restoring trust in an industry scarred by scandal.

The practice of ‘last look’, under which market-makers back away from trading at prices previously quoted to clients, will be the subject of a review by the newly-created Global Foreign Exchange Committee, set up to coincide with the launch of the FX global code of conduct in London on May 25.