The Libyan government invested at least $500m with Sir Allen Stanford, the Texas businessman accused by the US government of operating a $7bn Ponzi scheme, court documents filed on Tuesday show.

Sir Allen, accompanied by his girlfriend Andrea Stoelker, flew to Tripoli in a private jet on January 25 this year to meet government officials, including Mohamed Layas, identified in the documents as the chief executive of the Libyan Investment Authority.