The U.S. Drug Enforcement Administration inappropriately paid an Amtrak employee more than $850,000 over 20 years to provide information on passengers who may be smuggling drugs, according a report from the Justice Department's Office of Inspector General.

The OIG also released a separate report saying the DEA arranged to pay a government airport screener to act as a confidential source. The screener, however, never provided information of any value to the DEA.

But the OIG's problem with these arrangements wasn't that transportation officials were reporting people's actions to the DEA. Instead, OIG said it made no sense for the DEA to pay these people for information, as they are already required by law to offer it up for free.

"The OIG determined that over a period of 20 years, the DEA paid the Amtrak employee $854,460 as of January 2014 for information that was available at no cost to the government in violation of federal regulations relating to the use of government property, thereby wasting substantial government funds," the OIG wrote.

The report did find, however, that the DEA went too far at one point by asking the Amtrak employee to gather "specific information."

The OIG made a similar argument in the case of the TSA worker.

"The OIG also found that TSA security screeners are obligated to report to law enforcement suspected criminal activity that they observe in the course of their duties," that report said. "Therefore, by registering a TSA security screener as a [confidential source], the DEA agreed to pay for information that the screener was already obligated to provide to law enforcement."

That report did say that the DEA inappropriately asked the airport screener to report passengers carrying large sums of money, "in exchange for a reward based on money seized by the DEA." That violated internal DEA procedures, and may have violated people's right to be free of unreasonable searches and seizures.

The OIG released an audit report last July on its findings in both cases up to that point.