Sinful Cargo is a serviceable crime drama involving illegal immigration. Alan (Conrad Nagel) is a Federal Agent sent to Hollywood to investigate the racket and gets involved with reporter Bobbie Reynolds (Eleanor Hunt) and her hapless cameraman Vince Barnett.
The suspicion is that a film production company run by Crane Wilbur and Jack La Rue which doesn't seem to make any films is really a front for the racket. With the help of Bobbie, Alan pretends to be an aspiring actor to get involved with the production company and see exactly what they are producing.
It's not the best of films, Vince Barnett's hapless cameraman is a one joke role and unfortunately that joke stinks. However the plot is interesting enough and Jack La Rue plays a good role. At times the film has the breakneck air of an adventure serial, which isn't a bad thing of course.
This was the first of four movies with Alan, Bobbie and Vince in these same roles, another film was 1937's Bank Alarm.