Umberto Bossi, the 75-year-old founder of Italy's anti-immigrant Northern League party was on Tuesday admitted to a Rome hospital with an irregular heart-beat.
"He was admitted to the A.Gemelli University Polytechnic after suffering arrhythmia," the hospital said in a statement, adding that Bossi was undergoing tests.
An Italian court last week jailed Bossi for two years and three months after finding him guilty of fraud while he led the Northern League party.
One of Bossi's four sons, Renzo, as well as the former party treasurer, Francesco Belsito, were also convicted and jailed in the case.
The defendants say they plan to appeal the court's verdict.
A second son, Riccardo , was tried separately in the same case last year. He received a 20-month prison sentence.
Bossi suffered a stroke in 2004 and stood down as Northern League leader in 2012 amid allegations he was implicated in the embezzlement of hundreds of thousands of euros of party funds to pay personal expenses.
Once a key ally of former conservative prime minister Silvio Berlusconi, Bossi served as reforms ministers in two of the media tycoon's governments. He is also a former member of the European Parliament.
