Newton has fired a fund manager following a regulatory probe into the rigging of share prices.
The identity of the fund manager has not been revealed.
A spokesperson for Newton said: 'We are not able to comment on individuals, but we can confirm that we have taken disciplinary action as a result of the activity.
'One employee was suspended at the time; this individual has since been subject to disciplinary action and dismissed.'
Last week the Financial Conduct Authority (FCA) said it was investigating four fund firms over the possibility they may have broken competition rules.
Newton, along with Artemis, Hargreave Hale and River & Mercantile, were alleged to have shared information by disclosing the price they intended to pay in relation to IPOs and placing shortly before share prices were set.
The main allegations are that in 2014 Artemis and Newton shared information about the price they intended to pay for shares in relation to an IPO.
According to the Sunday Times, the £240 million float of the online holiday company On the Beach is one of the firms at the heart of the FCA probe.
The company, which listed in 2015, is said to be one of three deals said to be investigated.
In a statement sent out last week in response to the FCA's investigation, Newton said it was 'cooperating fully with the regulator', It added the probe focused on a very small number of its UK equity-focused strategies and the activity surrounding two initial public offerings and a placement in 2014 and 2015.
‘There has to date been no loss to any clients/investors as a result of the activity, and we do not anticipate any loss in the future,' Newton said.
‘We take compliance matters seriously and are committed to ensuring that our business is managed with the highest commitment to legal and ethical standards.’