Prominent Iranian documentary film-maker and women's rights activist Mahnaz Mohammadi has been jailed for five years, charged with collaborating against the state with the BBC.

Mohammadi's detention comes on the fifth anniversary of the bloody crackdown that followed the 2009 presidential election, when tens of thousands took to the streets to claim the election had been rigged. Hundreds were arrested, many of whom, including the main opposition leaders, remain in custody.

President Hassan Rouhani has come under considerable pressure to release Mir Hossein Mousavi and Mehdi Karroubi from house arrest, but has been prevented by Iran's hardline judiciary, which is independent of his administration and reluctant to let the unrest of the 2009 protests heal.

Mohammadi, director of the 2006 award-winning documentary Travelogue, was summoned earlier this month to Tehran's notorious Evin prison to begin her five-year sentence, initially handed down in October 2012 and later upheld in the appeals court.

The film-maker and actor has been found guilty of assembly and collusion against national security, and propaganda against the state – charges that have been brought on a number of opposition figures and activists in recent years.

Mohammadi has denied any collaboration with the BBC – an organisation Iranian authorities suspect of being a British espionage tool – and has expressed fear her detention is related to her work for women's rights.

"I have never worked with the BBC, and none of my films have ever been broadcasted on this network," the film-maker told the International Campaign for Human Rights in Iran (ICHRI) earlier this month. "I have also been charged with having relations with al-Jazeera English, German and American media, Radio France International, and Voice of America."

Iran has a history of arresting and intimidating people for alleged links to the BBC, in particular its Persian service, which is watched by millions across the country. BBC Persian's staff in London aren't immune to intimidation – with their families in Iran routinely summoned and interrogated, even since Rouhani took office last year.

In September 2011, at least six people were detained in Iran, accused of collaborating with the London-based BBC Persian service. The BBC denied the detained individuals had worked for them, but said they had aired films produced independently by them. It was not clear if Mohammadi was among those targeted in 2011 or if any of the film-makers arrested are still behind bars.

In January this year, the authorities repeated similar accusations against a number of activists and bloggers. In July 2009, Moahmmadi was detained at a memorial reception held for Neda Agha Soltan, a young woman whose death epitomised Iran's strive for freedom.

Mohammadi said in an interview with ICHRI that she was under pressure to confess to crimes in exchange for freedom.

"My interrogator wanted me to confess to receiving money from BBC Persian in return for working against the Islamic Republic of Iran, but because I had never done this and had no ties to the BBC at all, I didn't confess. The gentlemen had prepared a scenario which I had to act out," she told the ICHRI.

"My interrogator was unable to find any evidence against me. In the end, he referred to my documentary film, Travelogue, which had received an award from [the Iranian] Truth film festival in 2006, and used it against me as evidence," she said.

"Judge Moghisseh [her judge] told me in court: 'You don't deserve to breathe the air of the Islamic Republic of Iran.' He told me to 'go to your hypocrite friends abroad.' Some lawyers told me this meant they wanted me to leave the country."

Last week, two videos emerged online showing senior figures from the elite revolutionary guard in a private meeting appearing to discuss their forces' involvement in the 2009 crackdown. The mass arrests were largely carried out by plain clothed officers.