*Uh oh, Nelly could be in BIG trouble.

As we reported, the St. Louis rapper’s tour bus was busted Thursday morning when authorities found heroin and marijuana. But he denies any knowledge of the substances on board.

“It is my understanding a member of my staff made an unfortunate decision to bring unlawful materials onto our tour bus that resulted in his arrest this morning,” he told TMZ.

According to the online tabloid, Texas police found 36 baggies of heroin and more than 10 pounds of weed on board, along with a loaded .45 pistol.

And he claims he didn’t know.

It looks like one of the road dogs, Brian Keith Jones, has taken the rap for this one, and was arrested for drug and weapon charges.

“Neither I nor anyone else on the tour bus was aware of his decision to bring these on board. Law enforcement officials did not press charges against anyone other than that individual.”