LONDON (Reuters) - Iran’s Revolutionary Guards have arrested at least 30 dual nationals during the past two years, mostly on spying charges, according to lawyers, diplomats and relatives, twice as many as earlier reported by local or international media.

Iran's national flags are seen on a square in Tehran February 10, 2012, a day before the anniversary of the Islamic Revolution. REUTERS/Morteza Nikoubazl/File Photo

The number marks a sharp rise since 2015, when an international nuclear deal raised hopes of detente with the West. In the years before that the number of dual nationals detained at any given time was in single figures.

It also points up a new trend as a majority of those arrested since then, 19 out of the 30, have citizenship in Europe. Previously most of the detainees were Iranian Americans.

Detainees’ relatives and lawyers said the Guards were using them as bargaining chips in international relations and to put off European firms that sought business in Iran after the government agreed the deal with world powers to lift sanctions.

The Islamic Revolutionary Guard Corps has vast business interests as well as being Iran’s most powerful security force and has criticized the government for handing contracts to foreigners.

The Guards did not respond to several requests for comment. The Iranian government referred Reuters to the judiciary, which also did not respond to repeated approaches.

Iranian authorities have previously denied holding detainees for ransom and accuse Western governments of holding Iranians on trumped-up charges.

Relatives of dual nationals detained in Iran, their lawyers and Western diplomats shared information such as name, date of arrest and any charges, on condition neither they nor the detainees were identified, citing fear of repercussions.

Iran does not routinely announce arrests or charges and does not recognize dual nationals, whose rights to consular assistance are enshrined in the U.N. Vienna Convention.

In all cases, the sources said the detainees had not carried out any espionage and were arrested only because of their second citizenship. They explained their willingness to share details by saying they had been kept in the dark by both the Iranian authorities and Western governments.

Several governments argue that maintaining a low profile is in the best interests of the detainees. “This is very much what guides our approach,” a UK government source said. Dutch Foreign Ministry spokeswoman Daphne Kerremans said identifying detainees “could get the prisoners into trouble”.

BREAKING SILENCE

Some relatives only break their silence once their initial hopes have been dashed.

The wife of Ahmadreza Djalali, a Swedish-based Iranian scientist arrested in 2016 after attending a conference in Tehran, decided to speak out in February.

“We were all hopeful that he would be released soon. He was calling us from jail, saying he had not been officially charged. They had told him that he would be released after answering a few questions,” Vida Mehrannia said by telephone from Stockholm.

“I made the case public to media after nine months when he was threatened with a death sentence by a prosecutor and went on a hunger strike,” she added.

Djalali was sentenced to death in October on espionage charges.

Swedish Foreign Minister Margot Wallstrom said at the time: “We will point out that this will affect the relationship with the EU, and this in a time when Iran and the EU need to cooperate, not least with the nuclear deal we have with Iran.”

The deal to lift sanctions in return for curbs on Iran’s nuclear program was international, but significant U.S. restrictions remained in place.

Official confirmation of new arrests sometimes emerges indirectly. Records of a session of the European Parliament in June 2017 showed three Dutch-Iranian nationals were in jail in Iran. Only one case has been reported.

Asked about the two unknown cases, Dutch Foreign Ministry spokeswoman Kerremans told Reuters the individuals were arrested in November 2012 and January 2016 and said government actions were mostly “aimed at ensuring an honest trial, not demanding release”.

“It is very difficult for the Dutch government to lend support since Iran does not recognize the Dutch nationality of the prisoners, and gives little to no information about them,” she said.

In January 2016, then-British Prime Minister David Cameron raised the issue of three dual UK-Iran nationals held in Iranian prisons in a phone call with Iranian President Hassan Rouhani, according to a transcript posted on the Downing Street website. Only two of those cases were known to the public at the time.

Contacted for comment, a UK foreign ministry spokesman declined to specify how many British-Iranian dual nationals had been arrested. London raised all cases with Iran at every available opportunity, he said.

Nazanin Zaghari-Ratcliffe, an Iranian-British aid worker employed by the Thomson Reuters Foundation, was arrested in April 2016 while on holiday in Iran and later charged with plotting to overthrow Iran’s clerical establishment.

The foundation and her family have repeatedly denied the accusations.

“The only thing that as a family we can do is to point out the injustice of this,” said her husband Richard Ratcliffe.

He and others said this week that Foreign Minister Boris Johnson had made inaccurate comments about her to members of parliament that had been seized on by the Iranian judiciary and used to frame her.

Johnson had said, “she was simply teaching people journalism.” He subsequently said “the UK government has no doubt that she was on holiday in Iran” and that his comments “could have been clearer”.

“My point was that I disagreed with the Iranian view that training journalists was a crime, not that I wanted to lend any credence to Iranian allegations that Mrs Zaghari-Ratcliffe had been engaged in such activity,” he said.

PRISONER EXCHANGE

In 2016, Iran released five U.S. citizens in a prisoner exchange as the nuclear deal was implemented.

One remained behind and six American citizens or permanent residents have been arrested since, their lawyers or relatives have told media, of whom one has been freed on bail.

A U.S. State Department official confirmed three cases, did not comment on two others and mentioned another detainee, Nizar Zakka, saying he was unjustly held and calling for his release without clarifying his U.S. status.

Asked for more details about Zakka and other detained US citizens and legal residents, the official said the safety and security of U.S. citizens abroad was a top priority, adding: “Due to privacy considerations, we have no further comment.”

In an October 25 letter to the U.N. Secretary General seen by Reuters, Zakka’s lawyer Jason Poblete said his client was a U.S. permanent resident and “is being held as a hostage, as are other innocent persons, to exact political concessions from the United States and other governments”, including on sanctions.

For its part, Iran says its nationals are detained unjustly in the West. Kazem Gharibabadi, deputy head of Iran’s Council for Human Rights, part of the judiciary, has said more than 56 Iranians are imprisoned in the United States and an unspecified number in other countries.

“Some of those are detained under baseless charges, including bypassing sanctions,” he was quoted as saying by state media on Sunday.

U.S. Department of Justice spokesman Wyn Hornbuckle declined to comment on Gharibabadi’s figure, saying the Justice Department does not track prosecutions by nationality and the U.S. government’s Bureau of Prisons does not track how many inmates have Iranian nationality.

He said inmates in U.S. federal prison “are serving sentences handed down by federal judges after thorough due process of law”.