The naked body of a scientist and model was found in her flat in Russia with her thumb cut off, authorities have claimed.
Russian biochemist Ekaterina Antontseva, 34, is believed to have been strangled or suffocated, according to law enforcement sources.
Her corpse was discovered by her construction entrepreneur boyfriend when he returned from a business trip.
A male computer game fanatic identified only as Artyom, 36, has been detained on suspicion of murdering the lecturer who worked at St Petersburg Technological Institute and as a part-time model.
Police found her severed thumb at Artyom's home after the suspect allegedly used her fingerprint to gain access to her phone.
Pretending to be the scientist, he reportedly sent messages to her boss saying she was feeling ill and wouldn't be coming in to work.
Police believe he also deleted messages between himself and the victim.
One theory officers have is that he owed Ekaterina money and they had argued about repaying it.
She was killed last Thursday, and gaps in the doors and windows of her flat were sealed in order to prevent the stench being noticed by neighbours, reports say.
According to pdmnews.ru, Dr Mark Shamtsyan, professor at St Petersburg State Institute of Technology, said: "She was a very good person, very sympathetic, we all loved and respected her, and now it's hard to talk about it.
"She also had hobbies, she was engaged in photography.
"But she also loved her work, she liked working with students.
"She was a good researcher and teacher."
He went on: "She worked for us part-time and did not come every day; two, sometimes three days a week. She was absent at a time when she should not be.
"When we realised, she did not come, we began to look for her, it was already Friday.
"And on the weekend we received information from the investigating authorities."
Russia's Investigative Committee has launched a murder investigation.