CAIRO, July 28 (Reuters) - A Libyan court passed a death sentence in absentia on Muammar Gaddafi's most prominent son, Saif al-Islam, on Tuesday for suppressing peaceful protests during the country's 2011 revolution that ended his father's rule.

The court also handed down in a televised session a death sentence by firing squad to Gaddafi's former spy chief, Abdullah al-Senussi, and his former prime minister, Baghdadi al-Mahmoudi.

The verdict on al-Islam was passed in absentia since he has been held since 2011 by a former rebel group in Zintan region that opposes the Tripoli government, which is not recognised by world powers.

(Reporting by Omar Fahmy; Writing by Ulf Laessing; Editing by Hugh Lawson) ((ulf.laessing@thomsonreuters.com; follow me on twitter @ulflaessing; Cairo newsroom; Reuters Messaging: ulf.laessing.reuters.com@reuters.net))

Keywords: LIBYA SECURITY/