Doctors treating Swiss ice hockey player Ronny Keller say he has been left paralyzed by his injuries sustained during a playoff game.

Swiss Paraplegic Centre doctor Michael Baumberger says Keller has sustained ``permanent spinal paralysis'' by damage to his fourth thoracic vertebra.

Bamberger says in a statement that Keller did not sustain head or brain injuries.

The Olten defender hit the boards head first in overtime of a second-tier playoff match against Langenthal on Tuesday.

Keller was treated on the ice and airlifted by helicopter to the specialist hospital at Nottwil, where he underwent surgery.

Swiss media reported that Langenthal player Stefan Schnyder has been questioned by police, and the hockey league is investigating his challenge with Keller.