LONDON (Dispatches) -- Britain will soon repay a decades-old debt of over 450 million pounds to Iran, the Iranian ambassador said on Friday, adding that the payment was not linked to the case of an Iranian jailed for subversive action.
"An outstanding debt owed by the UK to Tehran will be transferred to the Central Bank of Iran in the coming days. The payment ... has nothing to do with Nazanin Zaghari’s case,” Hamid Baeedinejad wrote on his Telegram channel.
Zaghari was detained in April 2016 in Tehran as she tried to leave Iran. She was sentenced to five years in prison after an Iranian court convicted her of plotting to overthrow the Islamic Republic.  
Britain’s debt to Iran dates from the 1970s, before the Islamic Revolution of 1979 toppled the U.S.-backed Shah. Iran paid up front for 1,750 Chieftain tanks and other vehicles, but most were never delivered because of sanctions imposed on Tehran after the revolution.
A British government official, who asked not to be named, said on Friday it was "speculation” that the money would be paid.
The Treasury said in a statement the money was frozen by a British court and could not be paid because of sanctions.
The Telegraph newspaper reported on Thursday that Britain was working on a plan to pay Iran the debt, as part of efforts to secure Zaghari’s release.
On Thursday, British Prime Minister Theresa May’s spokesman denied there was any link between the debt and the convict’s case. Tehran also dismissed the Telegraph report.
In 2009, the International Chamber of Commerce ordered Britain to repay Iran for the undelivered vehicles, but UN and EU sanctions prevented that.
Iran’s Foreign Ministry spokesman said Wednesday that a range of issues would be discussed with Britain during a visit to Tehran this month by Foreign Secretary Boris Johnson.
British media have said Zaghari worked for the Thomson Reuters Foundation. However, Johnson said in a statement to a parliamentary committee last week that Zaghari had been "simply teaching people journalism.”
Johnson's remarks amounted to an accidental confession that Zaghari was plotting against the Iranian government, but British authorities described them a gaffe.