The 29-year-old had allegedly been recruited by Ukrainian special services and promised $100,000 and travel to the European Union, the news agency Tass reported, citing the country’s domestic spy agency, the FSB.
The man was arrested in the village of Chernoye in the Balashikha district of Moscow, the news agency Ria reported, citing interior ministry spokeswoman Irina Volk.
Kirillov, the head of the military’s chemical, biological and radiological weapons unit, was killed in an explosion along with his assistant as the two men left a building in a residential area in south-east Moscow on Tuesday.
A source in Ukraine’s SBU security service said Kyiv was behind the attack.
MA/PR