(a) Any member of a duly organized state, county or municipal peace unit of another state of the United States who enters this State in fresh pursuit, and continues within this State in such fresh pursuit, of a person in order to arrest the person on the ground that the person is believed to have committed a felony, a misdemeanor or a violation of the motor vehicle code in such other state, shall have the same authority to arrest and hold such person in custody, as has any member of any duly organized state, county or municipal peace unit of this State, to arrest and hold in custody a person on the ground that the person is believed to have committed a felony, a misdemeanor or a violation of the Motor Vehicle Code in this State.
(b) This section shall not be construed so as to make unlawful any arrest in this State which would otherwise be lawful.