The Porsche 961 was the racing version of the 959 supercar. While the 959 rallye car was also internally called 961, publicly only the circuit racer was called 961. Only one 961 was built. It had 959 prototype chassis number which in turn was from the 1985 911 Turbo chassis number sequence: WP0ZZZ93ZFS010016.
19Bozzy92 YouTube channel managed to film the 1986 Porsche 961: the only Porsche 959 factory race car in existence!