ALBANY — For the first time in New York, an appellate court ruled yesterday that someone who prevents a good samaritan from aiding another person may be held liable for the resulting physical harm.

While there is no common law duty to help a person in peril, the Appellate Division, Third Department, held in a unanimous decision by Justice Karen K. Peters that there is a legal duty to refrain from interfering with a rescuer who is willing and able to render necessary assistance.