Hawaii County police are awaiting toxicology results in the suspected fentanyl overdose death Thursday of a 56-year-old Hilo inmate whose 41-year-old cellmate, Izaiah Shields, allegedly smuggled fentanyl inside his body onto a plane and into the Hawaii Community Correctional Center.

Shields could be charged with manslaughter in connection with the death, depending on the toxicology results, said Hawaii County Police Capt. Rio Amon-Wilkins. The preliminary autopsy results showed no signs of trauma, but it appears Steven Mario Delgado died of a drug overdose, he said.

Police and Homeland Security had been investigating Shields and his girlfriend, Moriah Goulette, 37, both of Kona, for a month when vice officers intercepted the couple Dec. 29 at Ellison Onizuka Kona International Airport after disembarking a plane from San Francisco.

Vice detectives executed a search warrant on Goulette’s belongings and found 4.7 grams of fentanyl powder in an aluminium water bottle, authorities said. She was arrested at the airport.

The two were then taken to Kona Community Hospital where they were X-rayed. That resulted in the discovery of “64.5 grams of packaged fentanyl concealed within Shields’ body, of which he removed of his own accord,” police said in a news release.

On Dec. 30, Goulette was charged with two counts of third-degree promotion of a dangerous drug. Shields was charged with first- and second-­degree promotion of a dangerous drug.

Bail was set at $10,000 for Goulette and $75,000 for Shields for the Kona incident.

Since Jan. 1 was a holiday, the pair continued to be held at the Kona cellblock. On Jan. 2 they made their initial court appearances and were then transferred to HCCC.

Shields shared a cell from Jan. 2 to Thursday with Delgado and a 33-year-old inmate who was not identified. While Shields was away — he had gone that morning to Kona for his initial court appearance — the other two cellmates were found unconscious in their cell at 1 p.m. Thursday.

Delgado and the younger inmate were transported to the Hilo Medical Center, where Delgado died. The 33-year-old was treated for drug intoxication and released.

Inside their cell, detectives found “a white, rock-like substance, believed to be fentanyl, along with three more items wrapped in latex, consistent with smuggling contraband/narcotics into the facility,” recovering another 57.03 grams of fentanyl.

Capt. Amon-Wilkins said, “Based on the totality of the facts of this case, it is logical to believe that it was still in (Shields’) body” when he was taken into HCCC.

After the overdoses, HCCC personnel searched Goulette and found a zip-type packet of fentanyl powder in her mouth, and when taken to the Hilo police cellblock, police found more fentanyl in her pocket, for a total of 1 gram of fentanyl.

Detectives conferred with prosecutors and charged both with first-­degree promoting prison contraband for both suspects in addition to drug charges.

Shields also was charged with first-degree promotion of a dangerous drug and third-degree promotion of a dangerous drug.

Goulette also was charged with two counts of third-­degree promotion of a dangerous drug.

Goulette’s bail was set at $45,000, while Shields’ is $85,000 for the Hilo incident.

Shields and Goulette are scheduled for preliminary hearing today in Hilo District Court.

Goulette is scheduled for arraignment in Kona Circuit Court on Friday.

Shields’ arraignment in Kona Circuit Court is set for Tuesday.