Seen in the video released by Russia’s Investigative Committee, 33-year-old Mr Gareyev told officers he had lashed out at Ms Karaglanova, with whom he says he had an intimate relationship, after she “repeatedly insulted and humiliated” him.
Mr Gareyev said he had given Ms Karaglanova money whenever they got together, and that she had begun mocking him at their last meeting.
“She told me that I was ugly and that even plastic [surgery] would not help me,” he said, saying she had told him it would take a year for him to save enough money for them to meet again.
“I could not stand it,” he added.
Mr Gareyev had started seeing Ms Karaglanova weeks earlier and had been seen on numerous occasions entering her apartment, Russia’s RIA news agency reported.
Investigators said earlier that CCTV footage had captured a man connected to Ms Karaglanova briefly visiting her property in the days around her disappearance.
A spokeswoman for Russia’s interior ministry, Irina Volk, said police had begun questioning Mr Gareyev days later.
According to a report in MK, Ms Karaglanova had recently started a new relationship and had planned a holiday to The Netherlands to celebrate her birthday on 30 July.
What do we know about Ms Karaglanova?
Ms Karaglanova held a residency at a medical school in Moscow and practised as a doctor specialising in dermatology.
She was also a prominent social media personality, regularly sharing images of herself with her 85,000 Instagram followers.
In this post from March, she wrote about her plans for redecorating her flat, trips abroad and “another important activity I’m thinking about, which I’m not going to talk about for now”.
End of Instagram post by katti_loves_life
Her posts also included various European locations as she travelled throughout the continent.