A senior security official at Russian oil firm Bashneft was shot dead close to his home on Tuesday, investigators said.
Vladimir Butorin, 57, who was in charge of protecting industrial secrets for the mid-size oil producer was found dead with five gunshot wounds, investigators from the Prosecutor General's office said in a statement.
The statement said a murder investigation had been launched, but did not mention a motive, Reuters said.
State news agency RIA Novosti cited investigators as saying the killing could have been linked to Butorin's work at Bashneft.
Butorin was in charge of Bashneft's economic security department, according to the statement. Spokespeople for Yevtushenkov's AFK Sistema holding company and Bashneft couldn't be reached immediately for comment.
Bashneft offered a 100,000 rouble ($3,355) reward for information on the killing, which took place in the city of Ufa in the Urals Mountains region of Bashkortostan, Interfax news agency reported.
Contract killings plagued Russia's oil industry in the early 1990s but have been relatively rare in recent years.
Bashneft is controlled by Russia's oil-to-telecoms group Sistema.