A New Jersey teacher will not be returning to her job this Christmas after she told a class of six- and seven-year-olds that Santa Claus is not real.

Officials said that the substitute teacher, whose identity is not known, had also debunked other holiday characters, including the Easter bunny and the tooth fairy, last week.

This upset her first grade students at Cedar Hills School in the north-eastern US state of New Jersey.

School principal Michael Raj sent a letter to parents on Thursday (Dec 6) apologising for the teacher's actions, local media reports said.

He added that he had spoken to the teacher about her poor judgment.

"As a father of four myself, I am truly aware of the sensitive nature of this announcement," he told local news website NJ.com.

Montville superintendent of schools Rene Rovtar confirmed in a statement on Tuesday to broadcaster News 12 New Jersey that the teacher would no longer be working in the district.

Ms Rovtar said that the she was troubled and disheartened over what had happened, adding that the "childhood wonder associated with all holidays and traditions" is special to her.

She also took to Twitter to share a photo taken with Santa Claus, with the caption "I believe".

A parent told News 12 New Jersey last week that her six-year-old daughter Addriana was extremely upset after hearing the teacher's words.

Ms Myra Sansone-Aboyoun said: "I was heartbroken. You know, my daughter is the biggest believer in the whole Christmas spirit of Santa and giving."

It was not clear if the teacher was fired or had left the district voluntarily.