MOSCOW (AFP) - The chief witness to the murder of Russian opposition leader Boris Nemtsov - the Ukrainian model who was his girlfriend and was at his side when he was shot - complained Monday of being kept under guard in Moscow.
Ganna Duritska, 23, said she had given all the information she could to investigators but they were preventing her from leaving Russia, citing concerns for her security.
"For three days they have escorted me in police cars to the Investigative Committee," Duritska told the Dozhd television channel, referring to the agency in charge of the probe. "They don't explain when I will be let go or for what reason I am kept here."
Nemtsov, 55, was gunned down close to midnight Friday in a heavily-policed area on a bridge just across from the Kremlin.
The killers are still at large, despite a citywide manhunt.
Speaking via a fuzzy Skype connection from a Moscow apartment, Duritska said she did not see where the assassin came from as the attack took place behind her.
But she did notice a light-coloured car quickly drive off, she said.
She said there had been no earlier indication of any danger, nor any sign of surveillance, adding that the first police car arrived 10 minutes after she called.
She said she was immediately taken in for questioning which lasted through the night, with data extracted from her phones by the investigators, adding that she was being questioned as a witness.
"I've done everything I could," she said. However investigators told her that it would be unsafe to leave Moscow.
"I don't understand why I am still on Russian territory, because I want to go to my mother who is ill and is in a difficult psychological state," she said.
Ganna's mother Inna Duritska, who lives in Kiev, said that her daughter's de facto house arrest meant investigators might be preparing to make her a pawn in the deepening Russia-Ukraine crisis.
"I am afraid that she will be accused of this murder because they need the Ukrainian trace. They can invent anything they want," she said.
Moscow and Kiev have been foes since the ouster last year of Kremlin-backed president Viktor Yanukovych and Russia's seizure of the Ukrainian Crimea province. Ukraine's current pro-Western government has also been battling a pro-Russian insurgency in the east since April.
"I'm afraid that my daughter will become a second Nadezhda Savchenko," Inna Duritska said, referring to the Ukrainian pilot who is on hunger strike in custody in Moscow, accused of involvement in the murder of Russian citizens during the Ukraine conflict.
"A loved one was killed before her eyes," she said, adding her daughter's relationship with Nemtsov began two-and-a-half years ago. "Boris was her great love."
"She is under huge psychological pressure. They checked her telephone and are threatening to take her to a polygraph in handcuffs," she added, saying her daughter called her in tears. "They have no right to treat her that way!"
Ukrainian foreign ministry spokesman Yevhen Perebyinis said the consul in Russia had been to see Duritska several times and that she has written a formal letter requesting her return home.
"The Ukrainian embassy has issued a note asking to ensure the lawful return of Duritska to Ukraine," he said.