London (CNN) -- The Duchess of York, who faces charges in Turkey for going undercover and secretly filming children at a state-run home for a 2008 documentary, canceled a recent trip to the United States because of the case, a source and her spokesman said.
The United States and Turkey have an extradition treaty and the cancellation raised the question of whether Sarah Ferguson is avoiding the United States because she fears being sent to Turkey.
The treaty, in fact, was a factor in her decision, a source close to Ferguson said. The source described the duchess as "pretty shaken" and "quite scared."
Ferguson's spokesman, however, said the duchess was advised she could travel to the United States, but her priority right now is to stay in Britain and focus on the case.
She feels the work she did in Turkey was completely valid and consistent with her ongoing support for humanitarian causes, spokesman James Henderson told CNN. Ferguson is consulting rights lawyers as well as attorneys in Turkey as she decides what to do next, he said.
The Ankara prosecutor's office in Turkey accused the duchess of violating the private lives and rights of five children while filming a program for Britain's ITV network, Turkey's semiofficial Anatolian news agency reported last week.
A hidden camera was used during Ferguson's visit to the Children's Nurturing and Rehabilitation Center outside Ankara. She wore a disguise of a dark wig and headscarf for the filming.
Discussing the case, the Ankara chief prosecutor asked for a prison term of up to 22 years, six months, Turkish state TV reported.
There were no details on when a trial might take place, if at all.
A UK Home Office spokesman said: "It is not our usual policy to comment on individual cases.
"However, the Home Office can confirm it has received a formal request for mutual legal assistance concerning Sarah, Duchess of York. It is not appropriate to comment further."
What Ferguson is accused of in Turkey would not constitute a crime in Britain.
The Duchess of York said in a statement: "I stand strong in the face of the rights of children, and I remain steadfast. Children are our future."
ITV News spokesman Grant Cunningham said Friday: "ITV was made aware yesterday through media reports of charges related to our program being raised again.
"Charges were raised in 2008 and we said at that time that we firmly stand by our program and our position remains unchanged."
The duchess was accompanied by one of her two daughters, Princess Eugenie, to film the ITV Tonight program in Turkey.
An ITV press statement at the time of the film's broadcast in 2008 said the duchess, as part of a reporting team, had gone "undercover in one of Turkey's worst institutions -- capturing images that will shock and horrify."
The "hard-hitting" program was intended to "help investigate the treatment of mentally and physically disabled children," ITV said.
The duchess and her other daughter, Beatrice, traveled to Romania to see how state orphanages run for the second half of the program.
Ferguson is a former member of the royal family, having been married to Queen Elizabeth II's son, Andrew, Duke of York. The couple divorced in 1996, after 10 years of marriage.
CNN's Talia Kayali, Bharati Naik and Laura Smith-Spark contributed to this report.