Iran sent nuclear equipment to Sudan, a classified Saudi memo released by WikiLeaks says. The revelation comes as the June 30 deadline approaches for a deal on Iran's nuclear program.

WikiLeaks released 60,000 documents last week, purportedly revealing classified communications between Riyadh and Saudi embassies in various countries. Saudi diplomats in Khartoum said Iran sent nuclear equipment to Sudan in 2012, including centrifuges.

"The embassy's sources advised that Iranian containers arrived this week at Khartoum airport containing sensitive technical equipment in the form of fast centrifuges for enriching uranium, and a second shipment is expected to arrive this week," Reuters quoted the February 2012 document marked “very secret” as saying. WikiLeaks said the leaked document is a cable from the Saudi embassy.

Sudan is not known to have a nuclear program. Nor is Iran believed to have shipped any nuclear equipment to Sudan in the past. The cable, which provides information about the shipment, does not give further details about how the embassy had learned about the alleged shipment.

There was a mysterious explosion in a Sudanese munitions factory in October 2012. The explosion destroyed a significant part of the building and killed four people.

While the Sudanese government blamed an Israeli airstrike, no nuclear dimension was believed involved in the blast. The Times of Israel reported Israel neither denied nor confirmed its involvement in the factory blast.

Israel has said Sudan plays a major role in the Iran-backed arms supply network for Hamas and Hezbollah. There was speculation the explosion was an attempt to destroy weapons.

The top secret documents also claim a number of Saudi students among their counterparts from other Gulf counties went to the Israeli Embassy in Washington. According to the documents, the visit was a part of an international education program. Albawaba reported Saudi Arabia dismissed the documents as false.

Iran hopes international sanctions will be lifted when a deal on its nuclear program is finalized. However, Western experts have said Tehran has yet to meet transparency requirements.