LAWRENCE -- An administrator at Central Catholic High School in Lawrence fired for violating the "school's policies pertaining to appropriate social boundaries between students and faculty," is now under investigation for allegedly raping a boy when he was a student at the school.

The firing of Andrew Nikonchuk, director of curriculum and instruction at Central Catholic, was originally announced April 25 in a newsletter to school alumni.

In the newsletter, which doesn't note any particular incident, Central Catholic's president Christopher F. Sullivan said that the school "has adhered to the state's mandated reporting laws and is cooperating fully with the Office of the District Attorney and local law enforcement."

The Associated Press reported last week that Lowell Police and the Middlesex County District Attorney's Office are now investigating allegations by a 2008 graduate of the school that Nikonchuk drugged and raped him in 2006.

Allegations involving two other staff members, dean of students and basketball coach Richard Nault and social-studies teacher John Housiantis, have also surfaced following the firing of Nikonchuk, resulting in both staff members being placed on leave, according to reports by the Eagle Tribune.

Nault allegedly sent inappropriate private messages to a former student, while Housianitis allegedly posted compromising photographs of himself on an adult website.

Another former student, who attended Central Catholic in the 1960s, alleged May 2 that he was sexually abused by four Marist Brothers at the school, as well as the late Father Paul Rynne at St. Patrick Parish in Lawrence, who previously faced accusations for abusing boys.

Now in his 60s, the man is being represented by well-known Boston attorney Mitchell Garabedian.