The father of ex-oil tycoon and Kremlin critic Mikhail Khodorkovsky has been questioned by Russian investigators probing the 1998 murder of a Siberian mayor.
Boris Khodorkovsky’s son Mikhail, who now lives in Switzerland, is considered a suspect in the case but denies any involvement.
Mikhail Khodorkovsky, once Russia’s richest man, was arrested in 2003 and convicted of theft and tax evasion in 2005. Critics saw this as punishment for opposing President Vladimir Putin, which the Kremlin denies. He was pardoned and released from prison in 2013.