ROME (Reuters) -Italy's former Prime Minister Silvio Berlusconi was admitted to Milan's San Raffaele Hospital on Thursday evening, a source from his Forza Italia party told Reuters on Friday.

       "He had to be admitted for a thorough clinical check-up," the source said, giving no further details.

       Berlusconi, 84, has been in and out of hospital since contracting coronavirus last September. He said at the time that it was "the most dangerous challenge" of his life.

       The four-times prime minister and billionaire businessman underwent major heart surgery in 2016 and has also survived prostate cancer.

       He was last hospitalised in May, when he spent five days at San Raffaele.

       (Reporting by Angelo Amante, Writing by Crispian Balmer; Editing by Giulia Segreti)