"The Diocese of Pittsburgh has received the subpoena from the US Department of Justice and will cooperate fully with any and all investigations of the sexual abuse of minors by clergy in Pennsylvania," Vaskov said in a statement on Thursday, as quoted by CNN.
The Archdiocese of Philadelphia in a separate statement also said it received a subpoena to produce certain documents, although it did not specify the subject matter of the request.
READ MORE: New Report Shows Sexual Abuse in Catholic Church Remains Unsolved — Cardinal
A senior Church official told CNA the crimes under probe include transporting minors across state lines to abuse them along with production and distribution of illegal pornography.
In August, a grand jury report revealed a massive cover-up of child sexual abuse and rape of more than 1,000 children by at least 300 Roman Catholic priests in the US state of Pennsylvania.