A 19-year-old has been arrested for reportedly threatening New York Knicks owner James Dolan online.

John Giamella, from Staten Island, was arrested and taken to a New York court on a charge of aggravated harassment after Dolan had complained to the police.

"It's officially time to die — I really hate James Dolan," Giamella reportedly posted on his Twitter account, according to CBS Sports.

Madison Square Garden's head of security was responsible for finding out about the comment and the safety of fans at the arena was used as one of the reasons behind the complaint.

The Knicks are yet to comment on the incident.