A former Allen & Overy associate has claimed that Goldman Sachs exploited its relationship with the Libyan Investment Authority (LIA) to sell more than a billion dollars’ worth of complex derivatives to the sovereign wealth fund, promoting risky investments which ended up making a significant loss.

The LIA has made a $1.2bn (£750m) High Court claim relating to nine large long-dated complex financial derivative transactions which the fund entered into with Goldman between January 2008 and April 2008.