The woman who was with Russian opposition politician Boris Nemtsov when he was gunned down near the Kremlin says she did not see the killer because he came from behind.
Anna Durytska, a 23-year-old Ukrainian model, left Moscow for Ukraine late on March 2 after three days of questioning during which she said she was under constant guard by Russian law enforcement authorities.
"Ukrainian diplomats in Moscow provided all the necessary assistance for her return home," Ukrainian Foreign Ministry spokesman Yevhen Perebyinis wrote on his Twitter feed.
Lawyer Vadim Prokhorov, who flew to Kyiv with Durytska, told journalists at the airport that she "needs to rest" after days of questioning following "the death of a person close to her."
Durytska told Ekho Moskvy radio in a telephone interview on March 2 that she had been questioned by investigators every day since Nemtsov was shot as they walked across a bridge just off Red Square late on February 27.
"I have given all possible evidence and done everything possible -- I have told them everything I know," she said in an interview that was interrupted when Durytska's guards told her they were taking her to Investigative Committee headquarters.
Nemtsov, 55, was a reformist politician who served as deputy prime minister in the 1990s and became a fierce foe of President Vladimir Putin, helping lead protests against his rule and authoring reports alleging massive corruption among senior officials.
Tens of thousands of people walked through Moscow to the site of his slaying on March 1 in a mourning march organized by the opposition.
Durytska told Ekho Moskvy she had met Nemtsov in a cafe at a mall close to the Kremlin and that they were walking to his home when he was killed on the Bolshoi Moskvoretsky Bridge.
In a separate interview with Russian internet and TV channel Dozhd, Durytska said that she was able to see a light-colored car leaving the scene when she turned back, but did not make out the model or license-plate number.
"I didn't see any attacker getting into the car, either," Durytska said.
She told Ekho Moskvy that after the killing, she ran to the driver of a public-utility vehicle nearby to ask him how to call an ambulance and police, but that she did not remember what he looked like.
"I was in a state of shock," she said.
Speaking to Dozhd via Skype, Durytska said her mother was ill, under stress, and anxiously awaiting her return.
Durytska said that she had known Nemtsov for three years and ruled out the possibility that Nemtsov's killing might have been linked to jealousy over their relationship.
Russian investigators said personal animus was one of several possible motives in the killing, which Putin called a "provocation" -- a term meant to absolve himself of any blame and suggest his opponents could have killed Nemtsov to blacken the government's reputation.
Durytska told Ekho Moskvy that investigators had told her she might have to take a polygrpah exam, but Nemtsov family lawyer Vadim Prokhorov said that her current emotional, psychological, and physical state would not allow it.
Fears Of Foul Play
Earlier, Durytska's mother, Inna Durytska, who lives in Kyiv, told Ukrainian channel TSN that her daughter's virtual house arrest made her fear foul play on the part of investigators.
"I think they want to accuse her, to set her up," she said.
"She is under constant guard, she can't even leave [the flat]," she said, adding she suspected investigators wanted somehow to tie Nemtsov's killing to Ukraine, where Kyiv is battling pro-Russian separatists in a conflict that has killed more than 6,000 people since April.
Ukrainian President Petro Poroshenko said on February 28 that Nemtsov told him about two weeks earlier that he planned to publish evidence of direct Russian military involvement in the conflict.
On the same day, the Russian Investigatve Committee said that Nemtsov's killing could have been related to the war, saying in a statement that "it is no secret that among both sides in the conflict there are radical people who have no allegiance to any authorities."
On March 1, the Investigative Committee said that because Durytska was a "direct witness" of the killing, "there are grounds to conduct further investigative activities with her."
"I am afraid that she will be made into a second Nadia Savchenko," Durytska's mother said, referring to the Ukrainian pilot who has been on hunger strike for 80 days in custody in Moscow.
Savchenko has been charged with involvement in the death of two Russian journalists in the conflict between government forces and Russian-backed rebels in eastern Ukraine. She says she was illegally transferred to Russia.