"Mojtaba Kian... who sent information related to the country's defence industry units to the enemy, was hanged early this morning," the judiciary's Mizan Online website reported.

It said he shared information related to Iran's defence capabilities during the nearly 40-day war.

The execution is the first directly linked to spying offences carried out during the war, which broke out on February 28 when US-Israeli strikes killed senior Iranian leaders, triggering retaliatory attacks by Tehran across the region.

Since the start of the conflict, Iran has stepped up executions for spying or collaborating with Israel and the US, although prior to Sunday all those hanged were sentenced for offences carried out before the war.

According to Mizan, Kian "sent multiple messages to hostile networks affiliated with the Zionist-American enemy, including coordinates and information on facilities producing parts related to the country's defence industries".

Mizan said he sent information to satellite television networks. It did not identify those networks, but Iranian authorities have frequently accused Persian-language media outlets based abroad of cooperating with Israel.

The Mizan report said one "targeted location" in Iran was struck during the war after Kian passed on information about its whereabouts.

"The sentence was carried out early this morning after completion of legal formalities," Mizan said.

The website said Kian's execution took place "less than 50 days" after his arrest, while his assets were also confiscated.

Iran carries out the second-highest number of executions in the world after China, according to rights groups including Amnesty International.

On Thursday, the country executed two men convicted of armed rebellion and membership in what authorities described as "separatist terrorist groups", a phrase often used to refer to Iranian Kurdish groups based in neighbouring Iraq's Kurdistan region.