Engineer Sergey Kitrish, 41, has been under interrogation in the days since the crash, which killed all 10 passengers on board including Prigozhin, who launched a mutiny against Putin in June.
Probe into engineer who carried out last-minute repairs to Prigozhin s doomed plane dailystar.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from dailystar.co.uk Daily Mail and Mail on Sunday newspapers.
The poignant last photo taken by the only woman who was killed when the plane reportedly carrying Wagner Group Chief Yevgeny Prigozhin crashed has appeared online.