The BBC is appealing to the United Nations to help protect the rights of its journalists in Iran after complaining that its attempts to lobby Tehran on the issue have failed.

The move follows years of alleged persecution and harassment by the Iranian authorities of journalists and their families. The BBC said the problem escalated last year when Iranian authorities opened a criminal investigation claiming the work of BBC Persian Service journalists was a crime against Iran’s national security.

This was accompanied by an asset-freezing injunction citing 152 named individuals, mainly current and former BBC Persian staff. The injunction prevented journalists and their families from buying or selling properties in Iran.

The BBC World Service, which controls foreign-language services including the BBC Persian Service, a TV channel based in London, received funding until 2014 from the Foreign Office, a factor that has fanned the Iranian establishment’s distrust of its employees.

The BBC alleges that Iranian measures have included the arbitrary arrest and detention of journalists’ family members, the confiscation of passports and travel bans preventing people from leaving Iran, ongoing surveillance of journalists and their families, and the spread of fake and defamatory news targeting individuals, especially female journalists.

The BBC director general, Tony Hall, said the corporation was appealing to the UN “because our own attempts to persuade the Iranian authorities to end their harassment have been completely ignored”.

Lord Hall said: “In fact, during the past nine years, the collective punishment of BBC Persian Service journalists and their families has worsened. This is not just about the BBC – we are not the only media organisation to have been harassed or forced to compromise when dealing with Iran. In truth, this story is much wider: it is a story about fundamental human rights. We are now asking the community of nations at the UN to support the BBC and uphold the right to freedom of expression.”

Jeremy Dear, the deputy general secretary of the International Federation of Journalists, said: “For many years, Iranian journalists have suffered, been forced into hiding, fled into exile, been arrested, jailed and subjected to routine harassment, violence and intimidation.

“Iranians now increasingly turn to the international media to find out what is happening in their own country. Targeting family members in Iran in an attempt to silence journalists working in London must be stopped. The international community must act now.”

The BBC World Service filed an urgent appeal to the UN special rapporteurs David Kaye and Asma Jahangir on behalf of BBC Persian staff last October.

The corporation said its journalists would address the human rights council session of the UN in Geneva this week to call on member states to take action to protect BBC staff and ensure their ability to report freely.