TEHRAN, (Reuters) – Iran has executed an Iranian businessman convicted of spying on the military for the Islamic Republic’s arch foe Israel, the judiciary said on Saturday.

Ali Ashtari was hanged on Monday. He was arrested in 2006 after working with Israel’s foreign intelligence agency Mossad for three years, a judiciary statement said.

State television broadcast what it said was a confession.

Tensions have run high in recent months between Iran and Israel, which has not ruled out military strikes on the Islamic Republic if diplomatic efforts fail to resolve a row over Tehran’s nuclear programme.

Israel, believed to be the only country in the Middle East with nuclear weapons, sides with the West in accusing Iran of seeking to build atomic weapons of its own. Iran denies this, saying it wants to use nuclear power to generate electricity. “Ali Ashtari, an Iranian who spied for the Zionist regime of Israel, was hanged on Monday morning,” the statement obtained by Reuters said. It said he had been detained at the end of 2006. He was sentenced to death in June. Iranian media had said at the time that Ashtari was a 43-year-old manager of a company selling communications and security equipment to the Iranian government.

An Israeli government official said in June that Israel had no knowledge of the case. Israel’s Foreign Ministry was not immediately available for comment on the case on Saturday.

“Ashtari, during three years of cooperation with Mossad, had carried out a wide range of activities in favour of Mossad and on some occasions he succeeded in creating good conditions for Israelis,” the judiciary said, without elaborating.

The statement said he had been given “special equipment” to contact Mossad. He picked it up when he visited foreign companies at exhibitions abroad. “This spy also confessed that Mossad agents gave him names of some managers and experts from sensitive military centres so he could convince them to travel abroad and meet Israelis … ,” the statement said.

State television showed Ashtari sitting down wearing an open necked shirt and sweater, delivering what a caption described as “confessions of Mossad spy Ali Ashtari”. “It was my mistake and perhaps I feared going to the Intelligence Ministry, and this fear was the reason why I kept choosing the wrong path,” he said, speaking into the camera. “Do not repeat the mistakes that I made.”

Iran has often broadcast confessions in the past from those accused of threatening state security.

Iran’s ISNA news agency said that before his execution Ashtari described his cooperation with Israel and said he “unintentionally” fell into a trap. He urged those involved in his line of business to be careful dealing with foreign firms and to consult the Intelligence Ministry, ISNA added.

Iran’s Mehr News Agency said Ashtari’s body had been handed over to his family and buried.

Iran’s official news agency IRNA reported on Saturday that a group of four “terrorists” with “Zionist equipment and methods” were arrested in west Iran and said they were planning to carry out assassinations. It did not say when they were detained.

Iran often accuses Israel and other foes, such as the United States, of trying to destabilise the Islamic Republic.