The Supreme Court turned away an appeal from a former Toronto stockbroker convicted in a multimillion-dollar securities fraud who says federal prosecutors should have turned over documents that might have helped his defense.

The justices Monday let stand an appeals court ruling that said prosecutors didn't have to share information about the drug use of a key witness against George Georgiou. The lower court sided with prosecutors who said defense lawyers could have discovered the publicly available records on their own.

Georgiou's lawyers said prosecutors had a duty to disclose the information if they were aware of it. Several former Justice Department officials backed his claim and urged the court to take the case.

Georgiou was convicted on charges of manipulating markets of four stocks, causing $55 million in losses.