Raj Rajaratnam, the Galleon Group LLC hedge fund co-founder convicted of directing the biggest insider trading scheme in a generation, said the use of wiretapped calls by the US raises “substantial” issues of law that should allow him to remain free during his appeal.

Rajaratnam, 54, who is scheduled to report to prison on Dec. 5, is seeking to remain free pending the outcome of his appeal, according to his lawyers. He was convicted by a jury in May and sentenced to 11 years in prison.