Mumia Abu Jamal
Mumia Abu-Jamal is serving a life sentence (Getty Images)

A New Jersey teacher was fired after allowing her pupils to write letters to a man serving a life sentence for murdering a police officer.

Marilyn Zuniga, a first-year teacher at Forest Street Elementary School tweeted that letters her pupils had asked to write to Mumia Abu-Jamal had been delivered to him in jail.

A former Black Panther and journalist, Abu-Jamal was formerly on death row and is serving a life sentence for killing police officer Daniel Faulkner in Philadelphia in 1981.

Dubbed the "perhaps the world's best known death row inmate" by the New York Times, human rights groups claim his trial was unfair and he is innocent. Abu-Jamal was recently in hospital with complications from diabetes.

After learning about the letters, school authorities suspended Zuniga with pay on April 10.

Supporters of Zuniga claimed she was teaching her students compassion, and academic Noam Chomsky and Pulitzer Prize-winning journalist Chris Hedges were among those who signed a letter calling for her re-instatement.

But critics, including law enforcement officials, criticised her decision to allow children to write to a "cop killer".

In her remarks to the school board, Zuniga said she should be allowed to return to the classroom. "My students need me in the classroom. My students have requested that I come back to the classroom," she said, reports NJ.com.

However other Orange residents argued Zuniga should not be reinstated. "Even when I heard that the letters were written... because of compassion, you could've written to somebody in a nursing home," Gloria Stewart told the board. "You could've written to someone else that was sick to show compassion."

Zuniga's lawyer Alan Levine said that client was considering legal action against the school for unfairly terminating her employment.

"They lost a teacher that everybody agreed was a remarkable teacher," Levine said. "There isn't a school district around that wouldn't be happy to have Marylin Zuniga teach in it."