A former president of Chaminade High School was suspended from serving as a priest due to sex abuse allegations that were deemed "credible," but the alleged victim declined to pursue charges, officials say.

The abuse allegations were made against Father James Williams, who resigned as president of the all-boys school in 2011. The Catholic order of the Marianist Province of Meribah says in a letter sent to Chaminade faculty and families that it suspended Williams from the order, and that he is no longer allowed to publicly serve as a functioning priest.

The order says it conducted a "vigorous, thorough and comprehensive investigation" after the allegations were made, and says it "deemed them to be credible."

Williams has denied the allegations.

The Nassau County District Attorney's Office says it received a letter from a diocesan attorney in February 2015 that referenced the allegations. The district attorney's office says it opened an investigation and spoke to the alleged victim, who is a former Chaminade student.

The former student was a legal adult at the time and did not wish to pursue criminal charges, the DA's office says. The two-year statute of limitations had expired in 2013, two years prior to the diocese's reporting of the alleged misconduct. At the time of the letter, the DA's office says Williams was believed to be living in Italy.

The DA's office says it received a nearly identical letter dated May 3, 2016, from a law firm representing the high school. A district attorney spokesman says the office contacted the victim again, who reiterated that he did not want to pursue charges and wanted to remain anonymous.

When Williams stepped down in 2011, the same year that the alleged misconduct took place, neither Williams nor the school referenced any wrongdoing. At the time, the priest wrote a letter to parents and staff that read in part, "I have found myself at a unique personal intersection, where my responsibility to address the needs of Chaminade High School as president and my vocation to respond to the needs of God's people as a priest compete with each other for time."

The Marianist order says Williams was a member of the prestigious school's faculty and administration since 1991.

The Nassau District Attorney's Office is urging anyone who may have any information regarding allegations of sexual abuse by Father Williams to call the office at at 516-571-3800 and ask for the Special Victims Bureau.