Buckingham Palace said it would investigate staff working for Britain's royal family following an after-party which the Sun newspaper reported ended in a "punch-up" and "bar brawl".
Workers attended an early evening reception at Buckingham Palace before heading to a nearby bar to carry on the celebrations.
But their partying got out of hand and police were called "after glasses were hurled and punches thrown", the Sun said.
Buckingham Palace said on Friday that palace officials were aware of an incident which had taken place outside the workplace following a reception at the official London residence of King Charles.
"While this was an informal social gathering, not an official Palace Christmas party, the facts will be fully investigated, with a robust disciplinary process followed in relation to individual staff and appropriate action taken," Buckingham Palace said in a statement.
- Reuters