Singer Lady Gaga performs on the Canal Plus television show ''Le Grand Journal'' in Cannes during the 64th Cannes Film Festival, May 11, 2011.[Photo/Agencies]

A New Jersey school employee was in trouble on Thursday after telling students they were being treated to an online chat with Lady Gaga but substituted an impersonator instead, authorities said.

The elementary school employee in Tenafly, across the Hudson River from New York, had promised students that the celebrity would give an anti-bullying talk via the Internet last month, officials said.

"Knowing how disappointed the children would be, without authorization the staff developer made arrangements for an impersonator to take Lady Gaga's place -- a clear lapse in judgment," said Lynn Trager, superintendent of Tenafly public schools, in a letter to parents,

Trying to keep up the illusion, the fake Lady Gaga told the students her webcam was broken and she could only interact via a text-based chat program.

The employee also handed out signed photographs of the singer, and the ruse was exposed when a student noticed the autographs were forged, she said.

"Although her actions were inexcusable, I do believe that this was a misguided attempt to reward the children" after they had prepared for a test, the letter said.

Trager said "appropriate action" was taken against the employee for violating the school's "highest moral standards of honesty and integrity" but would not provide any details as it was a personnel matter.

Lady Gaga, who has risen to worldwide fame with such hits as "Born This Way," often speaks out against discrimination and bullying, saying she was a victim at school.

Lady Gaga had not been aware of the situation, a spokeswoman said.

"She had no knowledge of this and is currently discussing plans to do something with the school, but nothing has been solidified yet," said Holly Shakoor, a spokeswoman for Lady Gaga, in an email to Reuters.