Reality Show That Cast Ryan Jenkins: Oops

Producers of the reality show on which accused murderer Ryan Jenkins appeared admits it didn't do a "full" background check. What's not clear ... did it do any background check at all?

51 Minds -- the company that produces "Megan Wants a Millionaire" -- admits it was not aware that Jenkins had been convicted of assaulting a girlfriend when he was cast on the show. This is always a problem when you have someone with violent propensities sharing a house with unsuspecting strangers.

A company rep tells TMZ, "Obviously, if the company had been given a full picture of his background, he would never have been allowed on the show."

51 Minds adds, "The company did have in place what it thought was a thorough vetting process that involved complete background checks by an outside company for all contestants on the shows." In the company's defense, it was just one little mistake.