Federal prosecutors says former newspaper baron Conrad Black should not be freed from prison on bail pending his appeal to the U.S. Supreme Court.

In court papers, prosecutors said Monday that Black will have to remain in prison for obstructing justice even if the high court throws out his conviction for defrauding shareholders in his Hollinger International media empire.

Black was convicted in July 2007 of mail fraud.

Black also was convicted of obstruction after jurors saw a videotape of him carrying key documents out of his office and driving off with them.