A man is in a critical condition in hospital after setting himself on fire in a park outside the New York courthouse where Donald Trump’s hush money trial is taking place.

Just after the jury of 12 plus six alternatives was seated on Friday, emergency crews responded to a park outside the Manhattan courthouse.

The man took out pamphlets espousing conspiracy theories and spread them around the park before dousing himself in a flammable substance and setting himself on fire, officials said.

Trump Hush Money
New York law enforcement and fire department personnel at the scene (Mary Altaffer/AP)

People rushed over to douse him with a fire extinguisher and try to bat the flames away.

Emergency responders then took him away on a stretcher.