The Duke of Cambridge, Prince William, contracted COVID-19 in April at a similar time his father, Prince Charles, was battling coronavirus, Kensington Palace sources have told the BBC.
Prince Charles tested positive for coronavirus in March.
In April he said he was "on the other side of the illness", which had caused "relatively mild" symptoms.
Kensington Palace has refused to comment officially on the reports of Prince William's coronavirus infection.
Prince Charles described dealing with coronavirus as a "strange, frustrating and often distressing experience, when the presence of family and friends is no longer possible".
The Duke of Cornwall self-isolated at his residence in Scotland for seven days.
British Prime Minister Boris Johnson also tested positive for coronavirus in March.
He initially reported mild symptoms, but later fought for his life in hospital after his condition worsened.
After three nights in intensive care, Mr Johnson recovered and returned to work in late April.
The United Kingdom, which has the biggest official death toll in Europe from COVID-19, is grappling with more than 20,000 new coronavirus cases a day.
Scientists have warned a worst-case scenario of 80,000 dead could be exceeded this winter.
Britain has officially reported 46,717 COVID-19 deaths, however figures from the Office of National Statistics suggests the number is closer to 58,925.
Mr Johnson announced on Saturday that the UK would enter national lockdown from Thursday until December 2 following a second wave of the pandemic.
On Sunday, senior Cabinet Minister Michael Gove said the lockdown could be extended even further, with several of his colleagues suggesting it could last into next year.
The new lockdown announcement came 10 days after Mr Johnson told UK Parliament it would "make no sense at all" to "turn the lights out with a full national lockdown".
Reuters/ABC
