Nazanin Zaghari-Ratcliffe, a British-Iranian woman arrested in 2016, and Anoosheh Ashoori, a British-Iranian man arrested in 2017, have been released by Iran and are returning to the UK on Wednesday to be reunited with their families, British Foreign Secretary Liz Truss confirmed in a statement.

Zaghari-Ratcliffe was accused of plotting to overthrow the Iranian government, and Ashoori accused of spying, charges they both have denied.

Earlier, British Labour MP Tulip Siddiq told the BBC that the two had already arrived at the airport in Tehran but remained "under the control of the Iranian Revolutionary Guard," and a deal to secure their freedom had not "been completed yet."

Another British national, Morad Tahbaz, has also been released from prison on furlough, and the UK will "continue to work to secure Morad's departure from Iran," Truss tweeted on the same day.

The UK released $530 million of its debts to Iran ahead of their release, according to Iran's semi-official Fars News Agency.