Authorities discovered marijuana, codeine on Juice WRLD's plane just before medical emergency: Police

Police discovered marijuana, liquid codeine and firearms on the plane.

Chicago rapper Juice WRLD suffered an apparent seizure that led to his death while authorities were searching his plane and luggage for drugs and weapons, police revealed Monday.

The department said federal investigators asked officers to meet the aircraft when it landed Sunday to assist in a search, but declined to say who may have tipped them off. While the search was happening, Juice WRLD, whose birth name is Jarad Anthony Higgins, began convulsing and going into an apparent seizure, police said.

Narcan, a life-saving drug that reverses the effects of an opioid overdose, was administered and he was rushed to a nearby hospital, where he later died.

The medical examiner's office said Monday afternoon it was too early to determine the cause of death.

"The Cook County Medical Examiner’s Office has determined that additional studies are required to establish the cause and manner of death for 21-year-old Jarad A. Higgins," the office said in a statement. "Additional studies include cardiac pathology, neuropathology, toxicology and histology. The cause and manner of death are pending at this time."

The rapper's single "Lucid Dreams" peaked at No. 2 on the Billboard Hot 100 chart in the summer of 2018, following the release of his debut album, "Goodbye and Good Riddance." Higgins' 2019 album "Death Race for Love" debuted at No. 1 on the Billboard 200 in March.

ABC News' Alex Perez contributed to this report.