Police are searching for a 23-year-old man who jumped the dock in the Lower Hutt District Court, knocking out a prosecutor chasing him.
They said Mohi Sabbath escaped about 3.50pm.
The prosecutor has been taken to hospital for observation.
Mr Sabbath is facing charges of possession of an offensive weapon, unlawful possession of a firearm and assault.
Police described him as dangerous and asked anyone who saw him to call 111 immediately.