The Financial Conduct Authority has written to MPs telling them it has made “substantial progress” on its almost two-year long investigation into the collapse of Neil Woodford’s flagship equity fund, but said it was likely to be the end of this year before its probe is fully complete.

In a letter updating members of the Parliament’s Treasury Committee, FCA chief executive Nikhil Rathi said the regulator’s investigation team has conducted 14 witness interviews and has gathered in excess of 20,000 “items of relevant material” from key individuals.