MINSK, April 6 (Xinhua) -- Belarusian Foreign Minister Vladimir Makei on Friday called for an objective investigation into the poisoning case of a former Russian double agent.

Belarus opposed the hanging of any labels before an objective assessment of what happened, Vladimir Makei told reporters, calling all relevant parties to work together for an investigation.

Former Russian intelligence officer Sergei Skripal and his daughter Yulia Skripal were found unconscious on a bench in a shopping center in the southern British city of Salisbury on March 4.

Britain has claimed they were exposed to a military-grade nerve agent called Novichok and held Russia responsible. Moscow has denied any involvement in it and called British accusations "completely unacceptable."