A priest has been arrested on charges of stalking late-night talk show host Conan O’Brien by writing him threatening notes on parish letterhead, contacting his parents and showing up at his studio, prosecutors said Wednesday.

The Rev. David Ajemian, a priest in the Archdiocese of Boston, was arrested last week while trying to enter a taping session of NBC’s “Late Night with Conan O’Brien” at New York’s Rockefeller Plaza, said Barbara Thompson, a spokeswoman for the Manhattan prosecutor’s office.

Ajemian referred to himself as “your priest stalker” in one note and complained of not being allowed in to see an earlier taping of the O’Brien show, court papers say.

“Is this the way you treat your most dangerous fans?” the note said.

The letters and e-mails, which started coming in September 2006, continued even after Ajemian was asked to stop and were “intended to cause annoyance and alarm,” Thompson said.

“I want a public confession before I ever consider giving you absolution — or a spot on your couch,” wrote Ajemian, who signed the notes “Padre,” Thompson said.

Ajemian also has been in contact with O’Brien’s parents, Thompson said.

A telephone message left Wednesday night at St. Mary-St. Catherine of Siena Church in Boston, which Ajemian gave as his address, was not immediately returned.

O’Brien is not commenting, an NBC spokesman said.

Slideshow: Celebrity Sightings The Boston Archdiocese said in a statement that Ajemian had been placed on leave and was no longer allowed to minister publicly. O’Brien has participated in fundraising activities for the archdiocese.

The priest and the late-night host may have attended Harvard University at the same time. O’Brien graduated in 1985, and Ajemian graduated from high school in 1979 before attending the Ivy League school, according to an alumni magazine published by his high school.

The priest could face up to a year in prison if convicted of aggravated harassment and stalking.