A teenager who was injured when a deadly bar fire broke out in a Swiss ski resort on New Year's Eve has died in hospital, taking the death toll to 41, the local public prosecutor announced.

"An 18-year-old Swiss national died at a hospital in Zurich on January 31," the Wallis canton's public prosecutor, Beatrice Pilloud, said in a statement.

No further information would be released at this stage, she added.

The fire at Le Constellation bar in Crans-Montana - a venue known to be popular with a younger crowd in the ski resort town, where the drinking age is 16 - also injured 116 people.

Most of the victims of the fire were young - eight were under the age of 16 - and many are still being treated in hospital for severe burns.