Israel's Walla news website revealed that Tel Aviv has informed the United States that it was "gravely" concerned by alleged nuclear cooperation between Saudi Arabia and China.
The website said senior Israeli intelligence officials had called their American counterparts to express their "grave concern" about the cooperation between Riyadh and Beijing.
According to the site, "unnamed" Israeli officials said there was a secret factory of primitive materials used in uranium enrichment in Saudi Arabia near the capital, Riyadh, explaining that the Wall Street Journal and the New York Times were the first to report on it, including satellite images of the factory.
The officials pointed out that the office of Prime Minister Benjamin Netanyahu deals with the file as "very sensitive" politically since Israel considers Saudi Arabia an important ally in the face of Iran.
The officials added that the Israeli intelligence services, the ministries of foreign affairs, intelligence and defence, and the Atomic Energy Commission are following the developments of the Saudi nuclear program.
"There are worrying indications, but it is not clear enough yet what exactly is going on in this facility," Walla said, adding that this issue "is also unclear to the Americans and the International Atomic Energy Agency".
The alleged secret plant is used to manufacture a raw material used in uranium enrichment dubbed "the yellowcake" which is not a violation of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), and Saudi Arabia is not obligated to inform the IAEA. However, Walla explained that this could be the first step towards launching an independent nuclear programme, adding that it is likely that it will develop into a military nuclear programme in the future.
According to Israeli officials, Saudi Arabia has cooperated with China, because the Chinese did not ask for guarantees that the programme would be purely civilian, which is what the United States always demands.