Bishop Thomas O'Brien, the former bishop of the Diocese of Phoenix, has denied allegations he sexually molested a young boy in the late 1970s and early '80s.

"Bishop O'Brien categorically denies the allegations," the diocese said Aug. 3. "According to Diocese of Phoenix records, Bishop O'Brien was never assigned to any of the parishes or schools identified in the lawsuit, and no specific information has been presented which connects Bishop O'Brien to the plaintiff.

Bishop O'Brien, 81, is accused in a lawsuit of sexually abusing the alleged victim several times at parishes in Phoenix and Goodyear, Ariz. from 1977-1982.

His accuser, now 47 and living near Tucson, has said he started having flashbacks of the abuse in September 2014 as he prepared for his son's baptism, his lawyer Tim Hale told the Associated Press.

"It has turned his life upside down," Hale said.

The Phoenix police department is investigating the allegation.

The diocese said it contacted the Maricopa County Attorney's Office "immediately" upon learning of the allegations in September 2016.

Because the matter is pending litigation, the diocese said it would not share additional information. It expressed commitment to protecting all young people.

"We are dedicated to providing a safe environment in which every individual is valued and honored as created in the image and likeness of God. Anyone who has been a victim of abuse or who may have information concerning these crimes is encouraged to call a local law enforcement agency."

The diocese promised continued prayers for victims of childhood abuse and pledged continued vigilance to protection efforts.

Bishop O'Brien's handling of sex abuse charges against church employees resulted in a 2003 immunity deal. He acknowledged that he allowed employees accused of sex abuse to continue to have contact with children.

That deal said a grand jury investigating sex abuse allegations against the Church did not find evidence that the bishop engaged in sexual misconduct. But the deal did not prevent bringing charges against the bishop if there were evidence he committed sexual abuse.

After 21 years as Bishop of Phoenix, Bishop O'Brien resigned in June 2003, after being accused of striking and killing a 43-year-old man with his car in a hit-and-run accident. The bishop did not stop to help the man or to report the accident. He told investigators he didn't realize he had hit a person, thinking the collision was with a dog, a cat, or a rock thrown at his window.

He was convicted of leaving the scene of a fatal accident, then sentenced to probation and 1,000 hours of community service.