CCTV footage shows a man entering the flat of a popular 24-year-old Russian beauty blogger whose body was found naked in a suitcase with her throat slit.
Instagram influencer Ekaterina Semochkina - also known as Ekaterina Karaglanova - was discovered on Friday wearing only a suspender belt in her rented Moscow flat.
Her distraught parents found her body after they became concerned that she had stopped answering her phone, according to reports.
Police are also investigating suspicions that the qualified doctor and popular blogger with 85,000 subscribers was murdered by her lover.
It has now emerged that she was being blackmailed over nude pictures which had been sent to her university classmates, according to a friend.
Investigators say that she had worked as an escort to pay her way through her medical studies and that the explicit photos were linked to this.
They are also checking if a man seen on CCTV footage entering and later leaving her apartment block is a "jealous former lover".
A friend called Oksana told Komsomolskaya Pravda (KP) newspaper: “She wrote that she could be killed.
“But I was comforting her, [telling her] that they would do nothing to her.
“I cannot believe that Katya [Ekaterina] not here any more.”
Another friend named Nina said she was being blackmailed by “unknown people” over naked pictures, according to KP .
Threats were coming from “dodgy” accounts on a Russian social media network, she said.
“They were saying she was a prostitute.”
Another friend Svetlana said that Ekaterina hid her private life and that her blog had taken off after she had nose job when she was 21.
“This was her dream,” she said. "As soon as she had this surgery, she started having photo shoots in underwear."
Russian channel REN TV obtained CCTV footage reportedly showing a man entering the block of flats with his face hidden by a cap.
Four hours later the man left with a smaller suitcase and it is believed that he removed her bloodstained clothes and a weapon used to slit her throat and stab her twice in the chest.
The man shown was wearing gloves despite it being 27C outside on Friday when police say she was killed.
Detectives described the crime scene at Ekaterina’s flat as spotlessly clean with no traces of blood and say there were no signs of a fight.
The footage has been studied by the Russian Investigative Committee, in charge of probing serious crimes.
Ekaterina went on a number of foreign trips and on July 22 posted pictures from Corfu.
She had intended to go to The Netherlands for a trip with a 52-year-old man to celebrate her 25th birthday, it was reported.
A friend named Marina Nikitina told REN TV: “Recently I noticed that she had changed a lot.
“There was information that somebody did not like her.
“She posted about it herself: ‘Someone is badly interested in my private life’.”
Committee official Yulia Ivanova said an investigation was underway to “establish all the circumstances of the committed crime and at detaining the person involved in it”.
One theory is that the killer had put her corpse in a suitcase intending to remove her body from the flat but then realised he might raise suspicions.
He then decided only to remove her bloodstained clothes and the murder weapon.
Ekaterina had been a beauty pageant contestant in Moscow as well as qualifying from the prestigious Pirogov Russian National Research Medical University.
She had started working as a medic in a hospital in the city.
Fans said she had a likeness to Hollywood actress and fashion icon Audrey Hepburn.
Her Instagram showed her posing in studios, or during trips, as well as occasional pictures from her day-to-day life.
Some pictures showed her in lingerie.
Another image showed her graduation as a doctor specialising in dermatology.
