The US Securities and Exchange Commission has issued a questionnaire to hedge fund managers in a new attempt to crack down on insider trading, which has become a principle area of focus for regulators.

John Nestor, director of the SEC's office of public affairs, said: "The SEC's New York office is piloting a new information request to help firms identify an adviser's access to non-public information, and the controls advisers may have put in place to prevent insider trading."