The Undercover Man 1949- Glenn Ford, Nina Foch James Whitmore. Barry Kelley Frank Tweddell

Determined Treasury Department investigator Frank Warren (Glenn Ford) goes after a ruthless mobster known as The Big Fellow. When a key informant is murdered, Warren pursues the gangster on charges of tax evasion. But, with a slick mob lawyer hampering him at every turn, and threats being lobbed toward Warren’s wife (Nina Foch), the lawman’s chances of achieving a conviction are slim to none. His only hope is that one syndicate bookkeeper will have the courage to turn state’s evidence.