The British Boxing Board of Control (BBBofC) has cancelled all public boxing under its jurisdiction until at least early April.
This includes the European welterweight title fight between Russia's David Avanesyan and England's Josh Kelly at London's O2 Arena on March 28, as well as the British light-heavyweight title fight between Shakan Pitters and Chad Sugden in Coventry on the same night.
The BBBofC had considered professional events in the UK taking place behind closed doors, but then ruled it out, meaning all shows have now been cancelled.
The BBBofC said in a statement: "With regard to the above and the statement made by the Prime Minister Boris Johnson, all public tournaments under the jurisdiction of the British Boxing Board of Control are unfortunately cancelled. Further consideration of the matter will take place at the beginning of April.
"We have a number of requests for tournaments to be held behind closed doors however, the practicality and logistics will be considered fully following advice from Board Medical Officers."
Promoter Hennessy Sports confirmed the European junior-lightweight title fight between Samir Ziani and Alex Dilmaghani -- scheduled for April 25 -- has also postponed.
The Golden Contract tournament, due to take place Friday and shown on ESPN, has also been postponed to a later date.
The European and British heavyweight title fight between Joe Joyce and Daniel Dubois, arguably the biggest fight in the UK in the first half of 2020, is due to take place in London on April 11 and shown on ESPN. Promoter Frank Warren confirmed to ESPN that Joyce-Dubois is still on, for now, until the BBBofC meets again to discuss the matter again in early April.
Other big heavyweight fights scheduled to take place in the UK are also in doubt.
WBA-IBF-WBO world heavyweight champion Anthony Joshua is scheduled to defend his titles against Bulgaria's Kubrat Pulev in London on May 20, while heavyweight contenders Dillian Whyte and Alexander Povetkin are due to meet in Manchester on May 2, and it was announced last week that Oleksandr Usyk will face Dereck Chisora at the O2 Arena in London on May 23.