The spokesman of Monte Paschi di Siena, the Italian bank at the center of an investigation into alleged corruption and fraud, was found dead at the bank's Siena headquarters, a judicial source told Reuters on Wednesday.

David Rossi was the head of the bank's communications unit.

A witness told Reuters his body, which had been covered with a sheet, lay beneath an open window overlooking a courtyard outside the building, a restored 14th century fortress.

Rossi, who was not under investigation himself, was among several people whose homes and offices were searched last month as part of a probe into the lender's purchase of Antonveneta in 2007 and subsequent losses linked to complex derivatives deals.

(Reporting by Silvia Ognibene; Editing by Alex Smith and Toni Reinhold)