Vatican pulls diplomat from US amid concerns about child pornography A U.S. request for waiving the priest's diplomatic immunity was denied.

 -- The Vatican has recalled one of its diplomats to the United States after being notified that he may have violated U.S. laws on child-pornography images.

The U.S. State Department notified the Holy See on Aug. 21 of the possible violation of pornography laws by the diplomat stationed at the Vatican embassy in Washington, D.C., a Vatican press statement on Friday said.

"The Holy See, following the practice of sovereign states, recalled the priest in question, who is currently in Vatican City," the statement said.

A U.S. State Department official told ABC News that the United States requested that the Vatican embassy in Washington waive diplomatic immunity for the individual, but the request was denied.

The State Department only asks for a waiver of diplomatic immunity when "the prosecutor advises that he or she would prosecute but for immunity," according to department guidance in a June 2015 handbook. State Department officials referred any questions about possible allegations of criminal wrongdoing by the diplomat to the Justice Department.

The Vatican said in its statement that it has opened its own investigation with "international collaboration."

The priest's name has not been released. The Associated Press has reported that he is a "senior member of the Vatican embassy staff."

The staff of the Vatican embassy or nunciature in Washington includes the ambassador, a French-born archbishop named Christophe Pierre, and under him, three counselors who support him, according to the Vatican yearbook.

The U.S. Conference of Catholic Bishops also weighed in on the matter, calling for "an immediate, thorough, and transparent investigation … in cooperation with law enforcement."

"We hope the Holy See will be forthcoming with more details," said the conference president, Cardinal Daniel N. DiNardo of Galveston-Houston, Texas, in a statement. "The protection of children and young people is our most sacred responsibility."

In 2015, a similar case involving a high-level Vatican diplomat in the Dominican Republic resulted in charges.

Archbishop Jozef Wesolowski became the first high-level member of the clergy to be formally charged with child sexual abuse and possession of child pornography by the Vatican's criminal court according to Catholic News Service. He was defrocked and died while awaiting trial in Vatican City.