Detained charity worker Nazanin Zaghari-Ratcliffe said she is being harassed by Iran's Islamic Revolutionary Guard Corps while awaiting a second trial under house arrest at her parents' home in Tehran.
Ms Zaghari-Ratcliffe filed a report to prosecutors in the Iranian capital alleging officers from the IRGC had turned up at the house and accused her of breaking the electronic tag she was fitted with after her temporary release from prison in March, The Guardian reported.
Her complaint was also sent to Britain's foreign ministry.
Ms Zaghari-Ratcliffe said that the IRGC did not have the authority to monitor her movements as a prisoner.
A dual British-Iranian citizen, Ms Zaghari-Ratcliffe has been detained in Iran since April, 2016. She was sentenced to five years in prison after being found guilty of plotting to topple the Iranian government.
Ms Zaghari-Ratcliffe, who worked for the Thomson Reuters Foundation – the media organisation's philanthropic arm – denied the charges. She was released temporarily from Tehran's notorious Evin prison on March 17 because of the coronavirus crisis.
Earlier this month, Tehran abruptly postponed a new trial Ms Zaghari-Ratcliffe was facing for allegedly spreading propaganda against the regime.
Her husband Richard Ratcliffe said it was increasingly clear she was being held as a hostage against a long-standing UK debt to Iran.
The debt dates back more than 40 years to when the shah of Iran paid Britain £400 million (Dh1.8 billion) for 1,500 Chieftain tanks.
When the shah was overthrown in 1979, Britain refused to deliver the tanks to the new regime but kept the money.
British Prime Minister Boris Johnson's spokesman said earlier this month that the government was raising concerns with Iran at the highest levels, calling the new charges indefensible and unacceptable.