Financier and cricket mogul Allen Stanford has been scheduled to stand trial in September for an alleged $US 7 billion Ponzi scheme.

Stanford was sent to a US prison hospital for drug addiction treatment in February after a judge ruled he was temporarily unfit to stand trial.

Government psychiatrists and Stanford`s legal team testified that he was suffering from bouts of delirium linked to his dependency on powerful anti-anxiety medication.

They found the 60-year-old was also depressed due to a brain injury he sustained during a 2009 jailhouse brawl, and recommended he be weaned off the drug.

The flamboyant Texan has pleaded not guilty to more than a dozen counts of fraud, money laundering and obstruction. He faces up to life in prison if convicted. The trial is set to begin September 12.

A self-described "maverick," Stanford hit international sports headlines by creating the eponymous Stanford Super Series Twenty20 cricket competition.

The USD 20-million winner-take-all match appalled many in the cricket world by challenging the sacrosanct traditional cricket establishment.

In Antigua, he was a larger-than-life figure, the island`s largest employer and the recipient of a 2006 knighthood. But after the allegations against him surfaced, much of his support dwindled and the England and Wales Cricket Board cut ties with him.

Stanford launched a $US 7.2 billion countersuit in February against federal agents alleging violations of his civil rights and illegal prosecution.

The complaint says the agents "undertook illegal tactics" including a civil prosecution by the US Securities and Exchange Commission "which was calculated to seize all his corporate and personal records, conduct a criminal investigation... and at the same time, seize and take all of Mr Stanford`s personal assets" to impair his defence.