One of the two suspects in the poisoning of an ex-spy in England is a trained doctor who works for Russian military intelligence and traveled to Britain under an alias, investigative group Bellingcat reported Monday.

The two Russians accused of poisoning a former double-agent and his daughter in the U.K. claim they were just in town as tourists.

British prosecutors said Wednesday they have charged two Russian men with the nerve agent poisoning of ex-spy Sergei Skripal and his daughter Yulia in the English city of Salisbury.