TBI special agents with the Drug Investigation Division are warning people of a deadly combination of drugs.

Two different pieces of evidence from ongoing drug cases contained a lethal blend.

The TBI said one evidence sample contained a combination of ketamine, tramadol, cocaine, heroin, and fentanyl.

Another sample was powder that tested positive for a mixture of methamphetamine, acrylfentanyl, and methoxyacetylfentanyl.

Forensic Scientists in the TBI labs have rarely, if ever, seen this toxic mix of drugs in evidence submissions, according to the TBI release.

“It’s the latest example of why no illicit street drug is safe. And with combinations of these extremely toxic drugs being mixed with each other, it’s a cocktail that has us very concerned. We need to remind the public again that these already-dangerous drugs are becoming more and more deadly," Assistant Director of the TBI’s Drug Investigation Division T.J. Jordan said.

The TBI issued a warning in October about a cocaine submission that tested positive for fentanyl.

MORE: TBI warns of fentanyl in cocaine after 3 samples test positive, 2 in Knoxville

Anyone struggling with drug addiction issues should contact the Tennessee REDLINE at 1-800-889-9789.