Although not an explicit charge, investors who exit Woodford’s Income and High Income portfolios will receive less money after the group implemented a dilution adjustment on the two funds.

The dilution adjustment means sellers now receive the bid price rather than the mid price for the funds.

The current dilution adjustment means investors are getting a bid price which is 0.32% lower than the mid price on Woodford’s High Income fund, and 0.34% lower on the Income fund.

The switch to bid price is only implemented under certain circumstances when a fund has seen a set level of redemptions – usually around 5% – which could impact existing shareholders. However Invesco and other fund managers can use their discretion to implement a change even if the 5% level has not been reached.

In a letter to investors Invesco Perpetual said: “Under certain circumstances, a dilution adjustment is applied to the price of Invesco Perpetual’s ICVC’s to protect existing shareholders from the impact of costs related to dealing resulting from subscription/redemption activities by other shareholders.”

The switch to bid pricing – something that was seen across a number of property funds during the financial crisis – comes after Invesco Perpetual last week revealed Woodford’s funds had seen about 4% of their assets withdrawn, equivalent to £1bn.

Redemptions have climbed on the news of Woodford’s departure, with the manager set to launch his own fund company next year.