Seaton’s body was found on a beach in Boscastle in September after he had been missing for over a week.
A fraud investigation is being carried into allegations that Seaton defrauded the firm out of £1.6m between 2001 and 2005.
Rowanmoor Pensions managing Ian Hammond says: “I can confirm that after David Seaton’s death the Board conducted investigations into his business activities and fraudulent activity against a single client was uncovered. This was reported to the police by the Board and is now subject to police investigation. As a result, we are unable to discuss details of the case at this stage.
“We are confident that this was a one off issue and affects one client only. Rowanmoor is fully restoring the missing funds so there will be no loss to the client. Rowanmoor Pensions is financially strong and continues to run as normal it discovered fraudulent activity involving David Seaton in an investigation of his business activities which followed his death.”
A spokesman for Wiltshire Police says: “We can confirm that we are investigating allegations of fraud and theft involving David Seaton. As enquiries are currently ongoing it would not be appropriate to comment further at this stage.”