BERLIN (Reuters) - Germany has summoned Iran’s ambassador to warn Tehran against spying on individuals and groups with close ties to Israel, calling such acts an unacceptable breach of German law.

The move came after the March conviction of a Pakistani man for spying for Iran in Germany went into force.

Mustufa Haidar Syed-Naqfi was convicted of gathering intelligence on Reinhold Robbe, the former head of the German-Israel Friendship Society, and an Israeli-French economics professor in Paris, for Iran’s elite Revolutionary Guards.

The Foreign Ministry summoned the Iranian ambassador to deliver the rebuke once the German constitutional court rejected his appeal. The meeting took place on Dec. 22 but was not disclosed until now.

“Spying on people and institutions with special ties to the state of Israel on German soil is an egregious violation of German law,” a ministry official said.

The official said Philipp Ackermann, acting director of the Foreign Ministry’s political section, had told the Iranian ambassador that “such activities would not be tolerated and were completely unacceptable”.

The foreign ministers of Iran, Germany, France and Britain are due to meet in Brussels to discuss a 2015 nuclear agreement with Iran and concerns about Iran’s crackdown on anti-government protesters.

Germany, which helped negotiate the nuclear deal, has sought to balance its interest in expanding trade ties with Iran with its commitment to human rights.

It has played a key role in European efforts to persuade Washington to keep the nuclear accord in place, an issue that will come up again this week, when U.S. President Donald Trump must decide whether to reimpose oil sanctions lifted under the agreement.

Germany’s domestic intelligence service, which handles counterespionage, highlighted Iran’s spying activities in its annual report in July, saying that Tehran was focused heavily on Israeli or pro-Jewish targets.

Separately, the German federal prosecutor’s office said it was examining whether charges could be brought against a senior Iranian cleric, Mahmoud Hashemi Shahroudi, the former head of Iran’s justice minister, who is receiving medical treatment in the northern city of Hanover.

Volker Beck, a former Greens lawmaker, had filed a complaint against Shahroudi with prosecutors, accusing him of committing crimes against humanity.

“The complaint has been received and it is being examined,” a spokesman for the prosecutor’s office said. He said it was unclear how long that legal analysis would take.

Robbe said: “It’s a slap in the face to exiled Iranians and others to see such a former leader of the Iranian regime being treated in Germany.”