Grant Thornton has been fined a record £4 million for serious ethical breaches after it allowed one of its former partners, who was still employed as a consultant by the firm, to join the audit committees of two of its clients, Nichols, the maker of Vimto, and the University of Salford.

The conflict of interest created by Eric Healey, who was a senior partner at Grant Thornton before he left in 2009, created “serious familiarity and self-interest threats” and resulted in the “loss of independence” in eight audits over four years.