Confusion surrounds the fate of Sakineh Mohammadi Ashtiani, the woman whose sentence of death by stoning for adultery in Iran triggered an international outcry.

Campaigners initially claimed victory last night after photographs from state-run Press TV showed her meeting her son, Sajad, at her home in Osku, north-west Iran, boosting hopes that she had been suddenly released. However, a preview of an interview with Mohammadi Ashtiani broadcast by the station late last night raised questions about whether she had actually been released from prison, or whether Iranian authorities had merely taken her to her home to collect evidence against her and film a confession.

In a short clip she is seen to say: "We planned to kill my husband."

Early this morning Press TV denied the reports that she had been released and said that she had accompanied a team of TV production of the news channel to her house "to recount details of killing of her husband at the crime scene."

Press TV said: "Contrary to a vast publicity campaign by Western media that confessed murderer Sakineh Mohammadi Ashtiani has been released, a team of broadcast production team with the Iran-based Press TV has arranged with Iran's judicial authorities to follow Ashtiani to her house to produce a visual recount of the crime at the murder scene."

Press TV hinted that Mohammadi Ashtiani will appear on its "Iran Today" programme on Friday night to "shed light on the higways and byways of the murder account with multiple interviews with people and individuals involved in the case."

The move came weeks after Iran signalled it might spare the life of Mohammadi Ashtiani, 43, a mother of two who has been in Tabriz prison since 2006, and who faced execution by stoning for "having an illicit relationship outside marriage".

An international campaign for Ashtiani's release has been launched by her son Sajad, who was later arrested along with her lawyer Houtan Kian and two German journalists who were arrested after trying to interview her family.

The extraordinary case brought an unwelcome focus on human rights in Iran at a time when the Islamic regime was seeking to return to normal after the unrest that followed Mahmoud Ahmadinejad's victory in a disputed presidential election in June 2009.

Ecstatic campaigners initially hailed the news. "This is the happiest day in my life," said Mina Ahadi of the International Committee against Stoning (Icas). "I'm very happy for her son, Sajad, who fought single-handedly and bravely in Iran to defend his mother and tell the world that she is innocent. I'm sure that this day will be written in Iranian history books, if not the world's, as a day of victory for human rights campaigners."

International pressure over Mohammadi Ashtiani's fate began with campaigning on social networking sites and was later taken up by mainstream media as protest rallies were held in London, Rome and Washington, with support from Amnesty and other human rights groups, as well as a star-studded cast of celebrities including Colin Firth and Emma Thompson in Britain.

Iran's friends and enemies tried to intervene. Brazil's president, Luiz Inácio Lula da Silva, offered to give Mohammadi Ashtiani asylum in his country, while the US secretary of state, Hillary Clinton, urged Tehran to respect the fundamental freedoms of its citizens. Britain's foreign office minister Alistair Burt condemned the laws used against her as "medieval."

Tehran hit back furiously. Kayhan, a conservative paper, called Carla Bruni-Sarkozy, the French president's wife, a "prostitute" who "deserved death" after she condemned the sentence.

Iran accused its critics of trying to turn a criminal case into something of wider significance. "It has become a symbol of women's freedom in western nations and with impudence they want to free her," the foreign ministry spokesman Ramin Mehmanparast protested last month. "They are trying to use this ordinary case as a lever of pressure against our nation."

Evidently feeling the heat, Iran described her as "an adulterous woman" and introduced new charges, portraying her as a murderer who killed her husband. Mohammadi Ashtiani was put on state TV three times to confess to her charges but human rights activists insisted she had been tortured.

But signs of a possible change of heart came after Mohammad Javad Larijani, a top adviser to the Iranian supreme leader, Ali Khamenei, visited the UN last month and invited the secretary-general, Ban Ki-moon, to visit Iran. Still, he compared Ashtiani's case with that of Teresa Lewis, who was executed by lethal injection in the US state of Virginia for arranging the murder of her husband and stepson.

Under Iranian sharia law, those sentenced to death by stoning are buried up to the neck (or to the waist in the case of men), and those attending the public execution are called upon to throw stones. If the convicted person manages to free themselves from the hole, the death sentence is commuted.

Mohammadi Ashtiani was convicted in May 2006 of conducting an illicit relationship outside marriage. She endured a sentence of 99 lashes, but her case was re-opened when a court in Tabriz suspected her of murdering her husband. She was acquitted, but the adultery charge was reviewed and a death penalty handed down on the basis of "judge's knowledge" – a loophole that allows for subjective judicial rulings where no conclusive evidence is present.

Five years ago when Mohammadi Ashtiani was flogged, Sajad, then 17, was present. "They lashed her in front my eyes and this has been carved in my mind since then," he told the Guardian before his own arrest.

Iran has rarely carried out stonings in recent years. But it executed 388 people last year – more than any other country apart from China, according to Amnesty International. Most were hanged.

Ten Iranian women and four men are on death row awaiting execution by stoning, among them Azar Bagheri, 19, Iran Iskandari, 31, Kheyrieh Valania, 42, Sarimeh Sajadi, 30, Kobra Babaei, and Afsaneh R.