A Rapid City, S.D., priest who was set to become the next Catholic bishop of Duluth has resigned following an allegation that he sexually abused a minor in the 1980s in South Dakota.

Pope Francis has accepted the resignation of Bishop-elect Michel Mulloy, the Diocese of Duluth said Monday in a statement posted on its website.

The pope appointed Mulloy as the 10th bishop of Duluth in June, with his installation set for Oct. 1.

But officials with the Diocese of Rapid City received word in August about an allegation against Mulloy concerning the sexual abuse of a minor in the early 1980s in Rapid City.

Rapid City Bishop Peter Muhich informed law enforcement officers of the allegation, and Mulloy was directed to refrain from ministry, according to a statement from the Rapid City diocese.

Muhich said in a statement that the accusation met the standard of church law for further investigation and the Vatican was notified. Mulloy received a summary of the allegation against him and subsequently submitted his resignation as bishop-elect, Muhich said.

Rapid City diocesan officials said they had received no other allegations of sexual abuse involving Mulloy.

"We grieve with all who have suffered sexual abuse and their loved ones," said the Rev. James Bissonette, diocesan administrator for the Diocese of Duluth, in a statement.

"I ask you to pray for the person who has come forward with this accusation, for Father Mulloy, for the faithful of our diocese, and for all affected."

Mulloy, 67, most recently served as vicar general and administrator for the Rapid City diocese. He studied at St. Mary's University and Immaculate Heart of Mary Seminary in Winona, Minn., and graduated from St. Paul Seminary in St. Paul.

Mulloy was ordained a priest for the Diocese of Sioux Falls in June 1979, according to the St. Mary's University news service. He served parishes in the Sioux Falls and Rapid City dioceses before joining the Rapid City diocese in 1986.

Bissonette will continue to serve as diocesan administrator in Duluth until a new bishop is appointed. He assumed that role after Bishop Paul Sirba, formerly a priest for the Archdiocese of St. Paul and Minneapolis, died suddenly on Dec. 1.

The Diocese of Duluth has more than 45,000 members spread across 10 northeastern Minnesota counties.

The Associated Press contributed to this report.