The Defence Secretary and a number of top UK military officers are self-isolating after the Chief of the Defence Staff tested positive for coronavirus last week.
Ben Wallace and the heads of the Royal Navy, RAF and Strategic Command were alerted by the NHS Test and Trace app of the potential infection after coming into close contact with General Sir Nick Carter last Thursday.
The meeting was held at the Defence Academy at Shrivenham, Oxfordshire, and despite adhering to social distancing measures, the men are said to still have come into close contact with Gen Carter, who tested positive the following day.
Among those at the meeting with Mr Wallace were First Sea Lord Admiral Sir Tony Radakin, Chief of the Air Staff Air Chief Marshal Sir Mike Wigston and General Sir Patrick Sanders, Commander of Strategic Command.
Military business will be temporarily conducted remotely while the senior officers self-isolate.
A spokesperson for the MOD said those potentially exposed were following "Government guidelines".
"The Chief of the Defence Staff has tested positive during routine COVID-19 checks," they added.
"Colleagues who were in a senior meeting with him last week, including the Secretary of State, are self-isolating in line with Government guidelines."