IOWA CITY, Iowa — A well-known Catholic professor will be allowed to return to teaching and the ministry with restrictions after an inquiry found he misbehaved sexually in the 1990s but not against minors, church officials in Iowa announced Tuesday.

The investigation found that the allegation against Father Robert “Bud” Grant did not involve a minor because the complainant was “above majority age” at the time, the Diocese of Des Moines said in a statement.

However, the inquiry did establish that Grant “engaged in behavior in select instances in the early 1990s” that violated the 6th Commandment and his priestly promises, the diocese said. The 6th Commandment admonishes believers not to commit adultery and the Catholic Church uses the phrase when speaking of sexual sins.

Citing the “seriousness of the misconduct,” Des Moines Bishop William Joensen imposed restrictions on Grant that include an order not to touch or meet alone with anyone under the age of 24. The diocese did not elaborate on why that age was chosen.

A monitor will also supervise Grant’s activities, Joensen said.

Grant has been cleared to return to teaching at St. Ambrose University in Davenport in the spring semester. He will also return to St. Andrew Parish in Blue Grass where he will offer sacramental ministry.

Grant didn’t immediately return a phone message left at his office.

An individual called a hotline operated by Attorney General Tom Miller’s office in June 2019 alleging abuse by Grant from 1992 to 1994, when he was a teacher and coach at St. Albert High School in Council Bluffs. The church launched an investigation and Grant was placed on administrative leave from his teaching and priest assignments in March this year.

County prosecutors in Pottawattamie and Scott declined to open criminal investigations because the statute of limitations had long expired.

The review board of the Des Moines diocese determined that the evidence did not meet the criteria necessary to take the case to the Vatican for further review or a canonical trial. The board reviewed the complaint, an investigative report conducted by a third party and consulted with experts in church law, the diocese said.

The restrictions on Grant will be in place for one year and will be reviewed and adjusted after that time as necessary, the bishop said.

Grant joined the faculty at St. Ambrose, a private school with an enrollment of around 3,000 students, in 1994. Known as “Father Bud,” he has taught environmental ethics and historical theology and is known for his activism on climate change and other social issues. He has also served as director of the Academy for the Study of St. Ambrose of Milan and of the school’s Master of Pastoral Theology program.