The mother of an Lebanese-American journalist killed in Turkey while working for an Iranian news agency suspects foul play in the death of her daughter, who perished in what Turkish officials say was a traffic accident.

Serena Shim, a U.S. citizen from Michigan and mother of two, was working for Iran's state-owned network Press TV when she was killed after the rental car she was riding in collided with a cement mixer Oct. 26 in the Turkish town of Suruc, near the Turkish-Syrian border. The accident came just days after Shim said she had been threatened by Turkish intelligence services, who accused her of being a spy.

"I believe my daughter gave her life for the truth," Judy Poe, Shim’s mother, told FoxNews.com Friday from her home in Harrison Township, Mich. "I absolutely suspect foul play."

Poe insisted her daughter's death was "no accident," and called on the U.S. and Iranian governments to investigate the crash. Poe, who claims she was in regular contact with Shim, said her 29-year-old daughter had been threatened by Turkish officials after reporting ISIS militants were being smuggled back and forth across the Syrian-Turkish border in the back of aid vehicles.

Poe did not elaborate on who, specifically, could have been involved, saying her daughter "feared for her life and had been threatened."

In a televised report days before she was killed, Shim said, "I am very surprised at this accusation [of espionage]. I've even thought of actually approaching Turkish intelligence and -- because I have nothing to hide -- I've never done anything aside from my job and I'd like to make that apparent to them."

"However, I am a bit worried because as you know, and as the viewers know, that Turkey has been labeled by Reporters Without Borders as the largest prison for journalists," Shim said. "So I am a bit frightened about what they might use against me."

At the time of her death, Shim was covering the ongoing war between Iraqi Kurdish forces and ISIS militants for control of the strategic Syrian town of Kobani. Shim was killed while traveling with a female cousin along a one-way, three-lane highway in Turkey's Urfa Province, according to her mother. Her cousin, who was driving Shim's car, did not sustain life-threatening injuries.

Photographs of the crash in Turkish media reports show what appears to be Shim's vehicle in a head-on collision with a large cement truck -- despite traveling along a one-way highway.

The images, Poe claims, show a "shoddy job" that "tell us everything," suggesting the scene was staged to look like an accident.

An article published on Press TV's website reports Shim was killed in a "suspicious car accident" near the Turkey-Syria border. Her employer wrote she was traveling to her hotel after reporting in Suruc when her rental car "collided with a heavy vehicle."

Neither the U.S. State Department nor the Turkish government have contacted Poe about her daughter's death, she said. The U.S. Embassy in Turkey called Shim's husband seven days after she was buried to "inquire if her body had arrived in Lebanon," according to Poe. Shim was buried in Beirut on Oct. 22.

"I want to know what happened to my daughter," Poe said. "I want at least an attempt from the Iranian government, which owns Press TV, and the U.S. government to investigate what happened in Turkey."

Turkish media outlets, meanwhile, are reporting that Poe's cousin, identified as Judy Irish, was responsible for the crash. An official report obtained by Hurriyet Daily News claims Irish was the "sole culprit" and the truck driver, identified as Şükrü Salan, was not in any way responsible -- a conclusion Shim's family does not accept.

Izzettin Kucuk, a regional governor, was quoted as saying the allegations against Turkish intelligence involvement in the crash are "completely baseless." He told Hurriyet Daily News the accusations were "attempts to put Turkey in a difficult situation."

The State Department told FoxNews.com it "does not conduct investigations into deaths overseas."

"We do closely monitor all foreign government law enforcements' investigations into deaths of U.S. citizens overseas," a State Department official said. "Likewise, in some cases, FBI may choose to assist a foreign government, upon the foreign government's request, or investigate whether a death may violate U.S. law."

Poe described the loss of her daughter, whom she affectionately called "Sassy," as painful "beyond words."

Shim was born in Michigan and raised in both Dearborn and Livonia, where she graduated from Clarenceville High School. She went on to attend the American University of Technology in Lebanon, where her biological father lives.

"She made a choice to expose the truth and sacrificed being away from her children," Poe said of Shim, who left behind a 2-year-old girl and 4-year-old boy.

"She had such a great sense of humor," Poe said. "She was very grateful to be able to do all the good that she did."