ROME (CNN) -- An autopsy has determined that actor James Gandolfini's death Wednesday was the result of natural causes -- a heart attack -- family friend Michael Kobold told reporters here Friday.
"There was nothing out of the ordinary," he said. "There was no foul play, there was no substance abuse, none of that."
The 51-year-old actor had arrived Tuesday with his son, Michael, at the five-star Boscolo Exedra Roma.
"Jim was happy, he was healthy, he was doing really fine," Kobold said. "He was on vacation with his son. He has an 8-month-old daughter. Everything was going great. I just spoke to him on Father's Day."
On Wednesday, the actor had visited the Vatican and dined at the hotel with his son, the family said in a statement read by Kobold.
After he had returned to his room, Michael Gandolfini alerted hotel staff that his father was not answering his knocks on the bathroom door, said Tiziana Rocca, head of a film festival that the actor was planning to attend.
Hotel staff then broke down the door to get to him and called an ambulance, Rocca said Michael Gandolfini had told her.
The body has been turned over to a funeral director for embalming, Kobold said.
Relatives were seeking to expedite the paperwork needed to repatriate the body on Wednesday or Thursday to New York, where a funeral was planned for Thursday, Friday or Saturday, Kobold said.
Gandolfini was to have traveled Friday to the Sicilian town of Taormina to receive an award at the Taormina Film Festival, set in the ruins of an ancient Roman arena.
Festival organizers said that, in place of the award ceremony, they would hold a tribute to Gandolfini's lifetime achievements.
CNN's Hada Messia reported from Rome.