The restaurant's website has been removed after staff were told of the closure over the weekend.
Opened on 1 September 2015 with general manager Scott McCaig and head chef Adrian Mellor at the helm, the restaurant replaced Le Chabanais, which had only opened less than three months earlier following a delayed launch due to problems with the extraction system. Once opened, the food and interior failed to impress the critics.
Le Chabanais had opened as the London outpost of Paris restaurant Le Chateuabriand. However, chef Inaki Aizpitarte and his team returned to Paris soon after the launch.
The original restaurant was conceived by Varun Talreja, a film producer, together with Aizpitarte and his partners Franck Audoux and Laurent Cabut.
At the time of the opening of 8 Mount Street, a statement from the business said: "It is with regret that the owners of Le Chabanais restaurant, which opened earlier this year on London's Mount Street, can confirm that the partnership with Inaki Aizpitarte and his partners at Le Chateaubriand has sadly ended."
The Caterer was unable to confirm whether the closure was temporary or permanent.