Two of the world’s leading drug makers have this in common: They both made the mistake of hiring James Wetta as a sales representative.

Their misfortune has been taxpayers’ gain. A two-time whistleblower, Wetta, 46, played a key role in the Justice Department’s eye-popping settlement agreements with Eli Lilly & Co in January 2009 and AstraZeneca PLC on Tuesday.

Combined, the companies agreed to pay a total of $1.9 billion after investigations into their promotion of drugs for off-label uses, or uses not approved by the U.S. Food and Drug Administration.

Wetta, 46, left both companies under a cloud, after complaining of shady sales tactics. He filed a complaint against Eli Lily after resigning in 2002 and was hired by AstraZeneca in a matter of months. He later filed a complaint against the U.K.-based drug maker in 2004, while the investigation of Eli Lilly unfolded behind the scenes.

One of his lawyers, Stephen Sheller, remembers getting a call from Wetta after he had moved to AstraZeneca. “He said, ‘Steve, I can’t believe it. It’s going on here, too.’”

Sheller admitted he was dubious. “We went round and round, and I finally said, ‘Let me get more information.’ It turned out he was right.”

For a time after Wetta was fired from AstraZeneca in 2005, he and his family lived hand-to-mouth as he tried to find work. Now he’s a millionaire, living in Reno, Nev.

Eli Lilly pleaded guilty to criminal charge of misbranding its antipsychotic Zyprexa and paid a criminal fine of $515 million, the largest ever imposed. The company paid an additional $800 million as part of a civil settlement with states and the federal government.

Under the False Claims Act’s quit tam provision, Wetta shared a $100 million cut with five other whistleblowers. (His lawyers declined to disclose his share.)

On Tuesday, the Justice Department announced that AstraZeneca PLC would pay $520 million to resolve allegations it improperly marketed the antipsychotic Seroquel. (The company denies the allegations.) Wetta stands to earn $45 million, though an undisclosed amount will go to the another whistleblower.

His lawyers at Duane Morris LLP ^[1] and Sheller, Ludwig & Badey PC ^[2] in Philadelphia, where the qui tam actions were filed, declined requests to interview Wetta.

Dow Jones has more on Wetta here ^[3].