Richard Fisher, president of the Dallas Federal Reserve Bank, said: "Senior officials of the Chinese government grilled me about whether or not we are going to monetise the actions of our legislature."

"I must have been asked about that a hundred times in China. I was asked at every single meeting about our purchases of Treasuries. That seemed to be the principal preoccupation of those that were invested with their surpluses mostly in the United States," he told the Wall Street Journal.

The Oxford-educated Mr Fisher

has been running a fervent campaign to alert Americans to the "very big hole" in unfunded pension and health-care liabilities built up by a careless political class over the years.

"We at the Dallas Fed believe the total is over $99 trillion,"

His warning comes amid growing fears that America could lose its AAA sovereign rating.