Jupiter Asset Management pulled around £300m from Neil Woodford’s £8.9bn income fund last month.
John Chatfeild-Roberts, head of Jupiter’s Merlin multi-manager portfolios, pulled the money after Mr Woodford endured a tough summer which saw his funds hit when the share prices of several of his holdings fell sharply.
Jupiter’s Merlin Growth, Merlin Balanced and Merlin Income all held investments in the Woodford Equity Income fund.
FTAdviser’s sister newspaper the Financial Times reported total redemptions were just under £300m.
Mr Chatfield-Roberts was one of the first investors to back Mr Woodford when he left Invesco Perpetual in 2013 to launch his own company.
But the Woodford Equity Income fund has lost 0.3 per cent over the past year and is down 4.9 per cent over the past three months.
This has been driven by falls in a number of shares Mr Woodford's fund owns, including Provident Financial, the AA, Allied Minds and AstraZeneca.
Mr Woodford is the second-largest shareholder in Provident Financial, a doorstep lender, but its share price fell nearly 70 per cent over the restructuring of its home credit business.
Last month Mr Woodford apologised to investors who had lost money in his funds this year, but said he was sticking to his opinion that the consensus view of the world is wrong.
Mr Woodford said the performance of the FTSE 100 this year has been driven by a tiny number of stocks, with eight shares delivering 50.5 per cent of FTSE All Share index performance or 4.15 per cent in total return terms year to date.
A spokesman for Woodford said: “The transaction was concluded in September and the current assets under management of £8.9bn reflects this.”