An employee of US hedge fund Moore Capital and another at Deutsche Bank have been arrested as part of the Financial Services Authority's largest operation against insider trading in the City of London, it has been revealed this afternoon.

The financial regulator today said in a statement that six men had been arrested on suspicion of involvement with a sophisticated and long-running insider trading ring. The FSA did not identify the names of those arrested, but said that they included two senior City professionals who worked in leading City of London institutions.