VATICAN CITY -- The former papal envoy to the Dominican Republic, who went on trial at the Holy See this summer for alleged sexual abuse of minors, died of a heart attack, according to initial autopsy results, the Vatican said Saturday.

A Vatican statement indicated that laboratory results, expected in coming days, could elaborate on the cause of the sudden death of Jozef Wesolowski, a 67-year-old Pole, Thursday evening at the Vatican.

The Vatican announced the death Friday.

After work performed so far, "and from the initial conclusions based on the macroscopic examination, a natural cause of death, due to a cardiac event, is confirmed," said the Vatican statement.

The Vatican prosecutor's office appointed a panel of three experts co-ordinated by a forensic medicine professor at Rome's Tor Vergata University to determine the cause of death.

A Vatican trial against Wesolowski was an opportunity for Pope Francis to show he's carrying out pledges to punish high-ranking churchmen accused of sexually abusing minors or covering up abuse.

Wesolowski never set foot in the tiny courtroom for the trial, held in the same building where he was residing. On the eve of the trial's opening, Wesolowski was hospitalized in intensive care in a Rome hospital. Citing privacy concerns, the Vatican would only say he was hospitalized for "sudden illness."

But before the trial was adjourned indefinitely for Wesolowski's illness, the court clerk's reading aloud of the charges gave a vivid idea of the case's gravity and sordidness.

Prosecutors alleged that Wesolowski "corrupted, through lewd acts, adolescents presumed to be between 13 and 16 years old, in order to carry out on them, and in their presence, sexual acts" and that at least once, the sexual abuse happened in a public place.