Two Sigma, a quant hedge fund with nearly $60bn in AUM, has put one of its researchers on leave after the employee tampered with the firm’s investment models, resulting in some clients losing money, according to a report by Bloomberg.

The report cites a letter to investors sent by the firm on Friday as confirming that a researcher had "engaged in intentional misconduct" which led to “gains to some client portfolios and losses to others.”

In the letter, the firm went on to say that it was still assessing the impact of the misconduct and that it is "prepaid to remediate appropriately" if it concludes that a fund incurred losses as result of the employee's actions.

According to Two Sigma, the incident is not expected to affect the accuracy of investor account statements, or interfere with the firm’s normal operations.

Two Sigma hit the headlines earlier this year, when a feud between the firm's co-founders John Overdeck and David Siegel was cited as a material risk to the business in a regulatory filing.