Rio Tinto director John Varley, 61, has resigned from the mining giant's board after being charged with conspiracy to commit fraud by the UK Serious Fraud Office.

Mr Varley was charged on Tuesday night with two counts of conspiracy to commit fraud by false representation, and one count of providing unlawful financial assistance.

John Varley resigned from the board of Rio Tinto this week after he was charged with fraud. Credit:Daniel Munoz

Mr Varley is the former chief executive officer of Barclays.

The charges come after an investigation by the Serious Fraud Office, which was first announced in August 2012 and were revealed in a statement released on Tuesday.