Alex King and Anna Shapiro apparently became ill at the Prezzo Italian restaurant in Salisbury on Sunday.
The first and second in line to the throne were reported to have ‘refused to attend’ a meeting with the President.
The Prince of Wales is set to be named the next head of the Commonwealth after the Queen. According to the BBC, Commonwealth leaders are thought to have agreed behind closed doors that he will take over the non-hereditary role from the Queen at some point. It was widely reported that the role might have been shared among the 53 Commonwealth leaders.