Russia's ambassador to Moscow said Britain's royal family had been recommended not to have any contact with the Russian embassy in London, the Izvestia newspaper reported.
Asked by Izvestia if there had been any contact with King Charles III, Russian ambassador Andrei Kelin said: "No, and I know that members of the royal family are advised not to maintain or enter into contact with the Russian embassy."
Buckingham Palace could not be immediately reached for comment outside of normal business hours.
Russia's struggling foreign relations
Russia's relations with the West are at the worst level since the lows of the Cold War after President Vladimir Putin ordered an invasion of Ukraine and the West imposed the most severe sanctions in modern history on Russia.
Kelin said most politicians in the West had become "one-day butterflies" who did little serious thinking about the future and were obsessed with scoring futile political points.
"This deprives them of understanding what will happen in a month and a year from now with Ukraine," Kelin said. "After all, if things go on like this, Ukraine will become a failed state, a black hole that will have to be patched up."
He said that Russian businessmen, including the so-called oligarchs who earned fabulous fortunes after the fall of the Soviet Union, no longer considered London to be a safe haven.
"No one now would consider the United Kingdom to be a safe haven; it turned out to be a pirate haven," he said.