According to the arrest warrant, investigators believe Capella allegedly uploaded child porn to a social networking site between December 24 and 27 while visiting a church in Windsor, Ontario, in 2016.
This, however, is not the first child porn accusation trailing the Vatican official's robe.
The Vatican recalled Capella from its US diplomatic mission in August after the State Department notified it of a "possible violation of laws relating to child pornography images" by one of its diplomats in Washington, DC.
In a September 15 statement, the Vatican indicated that despite the high-ranking priest not being named outright in the US notification, the "priest in question" was ordered back to Vatican City to allow them to launch their own investigation.
No mention of the ongoing Canadian probe was mentioned in the Vatican's statement.
With the accused priest currently residing in Italy, Windsor police have not said whether they will pass their case on to Interpol or if extradition proceedings would be launched — per ABC News, the Vatican does not extradite its citizens.
"This is a serious issue. We hope the Holy See will be forthcoming with more details," Cardinal Daniel DiNardo, president of the US Conference of Catholic Bishops, said in a statement Friday. "While we don't know all the facts, consistent with our Charter, we reaffirm that when such allegations occur, an immediate, thorough, and transparent investigation should begin in cooperation with law enforcement and immediate steps be taken to protect children."
Speaking to the Washington Post, Reverend Thomas Reese, a columnist with the Religion News Service, says there are two systems through which the Vatican handles its legal matters: church law, which could cause Capella to lose his clergy status if found guilty, and Vatican City civil law.
Under the Vatican's criminal law, possession of child pornography could land an offender in prison for two years on top of a fine of $12,000. Producing and distributing are subject to more severe punishment.
Capella, who was ordained in 1993, worked at the Vatican's Washington, DC nunciature, a diplomatic mission of the church to the US, since the summer of 2016 until his recall last month, Crux Now reported. He has also worked as a diplomat of the Vatican in Hong Kong and Italy.