Israel suspects Venezuela and Bolivia of supplying uranium to Iran, according to a foreign ministry document leaked to media.
"We have information according to which Venezuela provides uranium to Iran for its nuclear programme," the document says.
"It seems that Bolivia is also a supplier of uranium to the Iranian nuclear programme," the document said, adding that Venezuelan President Hugo Chavez has played a key role in boosting Iran's ties with Bolivia.
The document said Venezuela is helping Iran dodge UN imposed sanctions.
It further claimed Iran is establishing cells of the Hezbollah militia in northern Venezuela and on Venezuela's Margarita Island.
Iran denies Western and Israeli suspicions that it is developing nuclear weapons, asserting that its nuclear programme is for peaceful purposes only. It is defying a UN demand to halt uranium enrichment.
Chavez has voiced support for Iran's nuclear programme.
The release of the document came one week before Israeli Deputy Foreign Minister Danny Ayalon is due to travel to Honduras to attend the Organization of American States (OAS) general assembly in what the ministry said would be an opportunity "to challenge the penetration of Iran and Hezbollah into the region."