OCEANSIDE, Calif. -- One of the county's oldest animal organizations is under investigation, 10News reported.

The Federal Drug Enforcement Agency is investigating Oceanside's North County Humane Society.

The North County Humane Society was founded nearly 70 years ago as a nonprofit organization -- funded mainly through private donations.

Like any other humane organization, it is subject to federal spot checks. The DEA conducted inspections in March and more information is expected.

A spokesperson for the DEA confirms agents conducted an investigation at the North County Humane Society regarding its handling of controlled substances. The DEA will not say what agents found, if anything.

According to a statement released by NCHS Tuesday afternoon, the DEA made three prearranged visits to the site and completed its review, but NCHS has not been notified of any conclusion to those visits.

10News visited Dr. Jennifer Luke, a veterinarian in Tierrasanta.

She is not associated with nor commenting on the NCHS case.

Luke did agree to explain how the DEA regulates controlled substances used at veterinary and humane facilities.

"I have to account for every CC in my vials," said Luke.

Luke says every office handling controlled substances must have an FDA-approved lock box permanently attached to something -- in her case, a concrete wall.

That box can only be opened with dual keys -- keys only Luke has access to.

A log book tracks every vial that comes into the office. Employees must see Luke when checking out drugs for a procedure.

When a drug leaves the cabinet, it's noted in a log book. Then each ounce of the drug used is also noted, which employee used it, which patient received it and how much. Why is the process so strict? Luke says it boils down to abuse.

NCHS also confirmed the recent resignation of executive director Stacy Steel, but calls it a separate event.

In her press release, board President Julie Moran said Steel was "invaluable to the growth and visibility of NCHS."