The Financial Conduct Authority said it had concluded there was "insufficient basis for taking any enforcement action", although it planned to raise a number of issues uncovered as part of the investigation with the firm.

Investigations into Prudential, Countrywide Assured, Old Mutual and Abbey Life were continuing, the FCA said in a statement.

The FCA added that "no inferences should be drawn from closure of Scottish Widows case concerning continuing investigations".

(Reporting by Simon Jessop; editing by Sinead Cruise)