By Polina Devitt and Kira Zavyalova
MOSCOW (Reuters) - Russian authorities on Thursday searched the offices of Mikhail Prokhorov, a tycoon whose newspaper has published revelations about people with ties to President Vladimir Putin, four sources close to his businesses said.
The sources said officials from the Federal Security Service and tax inspectors conducted the searches at Onexim Group, which manages Prokhorov's assets.
According to Forbes magazine, the 50-year-old is Russia's 14th richest person with $7.6 billion of wealth. He is also the owner of N.B.A franchise the Brooklyn Nets, previously known as the New Jersey Nets.