The SEC filed a complaint against Rio in 2017 with allegations that it had fraudulently concealed the decline in value of the business. Rio had acquired Riversdale mining for $3.7 billion in 2011, on the premise it would be able to barge 30 million tonnes of coal per year down the Zambezi river, and rail a further 12-15 million tonnes of coal per year to port. But it failed to secure government approvals, and discovered the resource was lower than expected, still raising more than $5 billion in 2012 before impairing the assets as coal prices fell the following year, when Chief Executive Tom Albanese departed.