A man questioned in the death of a Latina mother killed in Turkey has told authorities he was having a sexual relationship with her.
The Turkish man, identified only as "Taylan," gave DNA and sperm samples to police investigating the death of 33-year-old Sarai Sierra, a New York City mother who was found last week beaten beyond recognition near ancient walls in Istanbul, according to Turkish Daily Vatan.
The man told investigators he had a consensual sexual relationship with Sierra before she was last seen on Jan. 21, according to the newspaper.
The man's account was questioned by Sierra's best friend, Magdalena Rodriguez, who told FoxNews.com she doesn't believe the man's claim.
"We know Sarai. We know she didn't run off with anybody," said Rodriguez, who originally planned to accompany Sierra on her solo vacation to Istanbul. "She would have told me. She would have said something."
Rodriguez, who backed out of the trip at the last minute because of financial reasons, said she was in constant contact with Sierra during the trip.
A freelance photographer from Staten Island, N.Y., Sierra traveled to Istanbul Jan. 7 and failed to return on a flight Jan. 21.
Turkish authorities say Sierra died from a single blow to the head. A local funeral company on Tuesday told the Hürriyet Daily News, an English-language newspaper in Turkey, that she had multiple injuries to her head and face.
Her body was found Saturday near remnants of the city's ancient walls. Turkish police said there appeared to be no sign of a sexual assault, though the New York Daily News reported she was found in only a shirt and underwear. Sierra's gold jewelry was still on her, but her tablet computer and cellphone are missing.
A source familiar with the investigation told FoxNews.com that Sierra had contacted "amateur tour guides" online in advance of her trip. Taylan was among the individuals whom she had communicated with, and the two were known to have met on Jan. 13, according to multiple Turkish media accounts. The pair had planned to meet by the Galata Tower on Jan. 21 -- the day she was last seen -- but Taylan reportedly told investigators that Sierra never showed up.
Rodriguez claims she and the family were aware of Sierra's online communications.
"We knew about the tour guides ... We knew she planned to meet them," she said, adding, "she's not one to just meet a random person and then wander away with them."
Samples reportedly taken from under Sierra's fingernails suggest she may have tried to fight off her attacker. A blanket was also found near the body, leading investigators to question whether she was killed in another location and then placed near the ancient walls, which are close to a highway.
Sierra's husband, Steven, is still in Istanbul, where he traveled last week to help in the search. The woman's body is reportedly being flown out of the country for free on Thursday by Turkish Airlines. Sierra's family sold many of the her photographs online to help pay for her funeral.
Any additional funds will go to Sierra's two young sons, who have not yet been informed of their mother's death.
Based on reporting by the Associated Press and FoxNews.com.