Three men have been arrested in Dubai in connection with the disappearance of a British businessman of Iranian origin who is feared to have been abducted and murdered.
The whereabouts of Abbas Yazdi, 44, remain unknown but the emirate's authorities said they had forensic evidence linking the suspects with his kidnapping "beyond doubt".
Mr Yazdi, who holds dual British-Iranian citizenship, disappeared from Dubai on June 25 after giving evidence via video-link to a tribunal hearing in the Hague related to a dispute involving the National Iranian Oil Company.
His wife Atena has reportedly been told that it was "likely" he has been killed amid claims that he was targeted by a hit squad.
The businessman has been accused several times of taking bribes from foreign oil companies seeking concessions on Iranian oil fields.
His case caused controversy last month after it was claimed that t he Serious Fraud Office (SFO) had handed over hundreds of files from Mr Yazdi's computers to the authorities in Tehran following a request made through the Home Office.
Former director of public prosecutions Lord Macdonald said at the time that he believed Mr Yazdi was murdered by the Iranians and raised concerns over British authorities assisting "an Iranian law enforcement agency notorious for human rights abuses".
The peer, who was involved in Mr Yazdi's case before the abduction, told The Times: "That the Home Office should have done this in respect of a British citizen who was (then) murdered by the Iranians is beyond belief."
The newspaper reported that in 2003 Mr Yazdi was investigated by the SFO over an oil deal, and his computer records were kept despite him being exonerated.
Foreign Secretary William Hague raised the disappearance of Mr Yazdi with his Iranian counterparts in July.
A Foreign Office spokeswoman said: "We welcome the arrests of three men by the Emirati authorities in connection with the alleged kidnapping of British/Iranian national Abbas Yazdi.
"The UK will continue to liaise with the Emirati authorities over the investigation."
A spokesman for the Metropolitan Police said counter-terrorism officers are involved in the investigation and the force is providing support to Mr Yazdi's family.
The UK has an international obligation to provide mutual legal assistance to other countries in certain circumstances, with requests received through the Home Office.
Both the Home Office and the SFO have refused to comment on matters of mutual legal assistance as a matter of policy.