A group of investigative journalists and researchers on Monday identified a military doctor employed by a Russian intelligence agency as one of two men suspected by the British authorities of trying to kill a former Russian spy with a potent nerve agent in Britain earlier this year.

The group, which named the other suspect in the poisoning about two weeks ago, identified the doctor as Alexander Yevgenyevich Mishkin. It said he was a graduate of an elite military medical academy who was recruited by a military intelligence agency widely known as the G.R.U.

Last month, British prosecutors filed criminal charges against two Russian men they say traveled in March to Salisbury and poisoned the former spy, Sergei V. Skripal, by smearing the nerve agent on a door handle at his home. Mr. Skripal’s daughter, Yulia, was also poisoned.

The authorities said the men, who were captured on surveillance video near Mr. Skripal’s home, had traveled to Britain using the aliases Alexander Petrov and Ruslan Boshirov. While the men were identified as G.R.U. officers, their true names were not disclosed.