VATICAN CITY -- The Vatican put its former ambassador to the Dominican Republic under house arrest Tuesday after opening a criminal trial against him, the first time a high-ranking Vatican official has ever faced criminal charges for sexually abusing youngsters.

Josef Wesolowski had already been defrocked in June after the Vatican's canon law court found him guilty of abuse and imposed its toughest penalty under church law: laicization, or returning to life as a layman.

On Tuesday, the Vatican City State's separate criminal court opened a preliminary hearing into his case and ordered him placed under house arrest.

A Vatican statement said Wesolowski presented medical documentation detailing health concerns that presumably prevented a more restrictive type of detention. The Vatican has a few small detention rooms inside its police barracks, but no long-term facilities.

The Holy See recalled the Polish-born Wesolowski in August, 2013 after the archbishop of Santo Domingo told Pope Francis about rumours that Wesolowski had sexually abused teenage boys in the Caribbean country. Prosecutors there say he allegedly paid boys to masturbate.

Dominican authorities opened an investigation, but declined initially to press charges since the Vatican had said Wesolowski enjoyed diplomatic immunity. Polish prosecutors as well opened an investigation.

A Santo Domingo court, though, took the first steps toward possibly charging him last month after the Vatican said he had lost his immunity when he was defrocked and could be prosecuted elsewhere.

The office of the Dominican Republic's attorney general said Tuesday it was requesting specifics from the Vatican about how it came to its decision to put Wesolowski under house arrest and open a criminal trial against him.

Spokeswoman Tessie Sanchez said Attorney General Francisco Dominguez Brito wanted more details from the Vatican before commenting further on the latest developments in Wesolowski's case.

In an August interview with The Associated Press, Dominguez welcomed the Vatican announcement that Wesolowski had lost his diplomatic immunity and could be tried by Dominican or other courts.

Wesolowski could face jail time if found guilty by the Vatican criminal court, which has jurisdiction over crimes committed within the tiny Vatican City State or by any of the Holy See's diplomatic personnel.

It is unclear where he would serve any possible term: inside the Vatican or in an Italian prison.

The case against Wesolowski has been closely watched, given the grave nature of the charges and the fact that the Vatican had faced criticism that it had shielded Wesolowski from Dominican jurisdiction by recalling him last year. In fact, many countries would have done the same with diplomatic personnel facing possible criminal charges abroad.

The case has also been a test of Francis' willingness to sanction even a high-ranking Vatican official for a crime the Holy See has long sought to blame on wayward priests, not direct representatives of the pope.

Francis has said no prelate, whether a priest or a cardinal, has any privileges when it comes to sex abuse.