The former chief financial officer of mining group Rio Tinto has stepped down from a role with the UK's M&A watchdog after being charged with fraud by the US Securities and Exchange Commission.

Guy Elliott spent more than 30 years with Rio Tinto, eventually becoming CFO. He announced his departure in mid-2012 and left in April the following year. Earlier in October, the SEC announced that Elliott, former Rio Tinto chief executive Thomas Albanese and Rio Tinto itself were charged with fraud for inflating the value of coal assets acquired for $3.7bn and then sold for $50m.