LONDON — A British man whose girlfriend died after they were both poisoned by a nerve agent thought to have been discarded by Russian intelligence officers in England went looking for answers at the Russian Embassy in London this weekend, asking, “Why did your country kill my girlfriend?”

The startling meeting — which at times seemed more like a friendly tour of the embassy in South Kensington, an affluent area in West London, than an inquisition of a representative of the government potentially responsible for the death of his girlfriend, Dawn Sturgess, in July — left more questions than answers.

The meeting between the man, Charlie Rowley, and Russia’s ambassador to Britain, Alexander V. Yakovenko, on Saturday was partly arranged by The Sunday Mirror, a British tabloid.

Mr. Rowley met with Russia’s envoy nine months after he and Ms. Sturgess were poisoned by a nerve agent that the authorities say was originally used to target a former Russian spy, Sergei V. Skripal, in March 2018. But Mr. Skripal’s daughter, Yulia, and a police officer were also sickened.