MONTGOMERY, Ala.  Donald Siegelman, former governor of Alabama, was ordered released from prison on Thursday by a federal appeals court, pending his appeal of a bribery conviction that Democrats say resulted from a politically driven prosecution.

In its order, the United States Court of Appeals for the 11th Circuit, in Atlanta, said Mr. Siegelman had raised “substantial questions” in his appeal of the case and could be released on bond from the federal prison in Oakdale, La., where he has served nine months of a seven-year sentence. The order did not say what those questions were, but his lawyers have argued for months that the bribery charge on which he was mainly convicted revolved around a transaction that differed little, if at all, from a standard political contribution.

Mr. Siegelman’s lawyers maintained that  as is standard in many white-collar crime cases  the veteran Democratic politician never should have been imprisoned in the first place while he appealed his conviction.

“He should not have been manacled and taken off in the night,” said his lawyer, G. Robert Blakey, also a professor at the University of Notre Dame, citing the ex-governor’s immediate imprisonment after his conviction, a point of contention for his supporters.