An Italian journalist detained in Iran last month has been freed and is on a flight back to Rome, the Italian government says.

Cecilia Sala, 29, was arrested on 19 December, three days after an Iranian engineer was detained by Italian authorities in Milan on suspicion of supplying drone technology that led to the deaths of US soldiers.

Reports said she had been held in solitary confinement in Tehran’s notorious Evin prison.

It is unclear what led to Sala’s release, however the news was broken by Prime Minister Giorgia Meloni’s officials who cited “intense work through diplomatic and intelligence channels”.

In the Italian statement, Meloni thanked “all those who contributed to to making Cecilia’s return possible”. She had personally told Sala’s parents of her release, it added.

Meloni had met US president-elect Donald Trump at the weekend, and the journalist’s detention was expected to be discussed.

Outgoing president Joe Biden is due to visit Rome later this week.