Israel paid Russia $1.2 million to provide the Syrian government with coronavirus vaccine doses as part of a deal that secured the release of an Israeli woman held captive in Damascus, according to Israeli media reports.
The terms of the clandestine trade-off orchestrated by Moscow between the two enemy nations remained murky.
But the fact that Israel is providing vaccines to Syria - an enemy country hosting hostile Iranian forces - has drawn criticism at home. It has also drawn attention to Israel's refusal to provide significant quantities to millions of Palestinians living in the West Bank and Gaza Strip.
Speaking at a news conference Saturday, Prime Minister Benjamin Netanyahu said "not one Israeli vaccine" was involved in the deal.
But he did not address the issue of whether Israel paid for Russian vaccines, and he said Russia insisted on keeping details of the swap secret.
The Prime Minister's Office has declined further comment.
Israel announced Friday it had reached a Russian-mediated deal to bring home a young woman who had crossed the border into neighboring Syria earlier this month. In exchange, Israel said it had released two Syrian shepherds who had entered Israeli territory.
As part of the prisoner swap mediated by Moscow, Israel paid Russia to supply Syria with an undisclosed number of doses of the Sputnik V vaccine, according to Israeli media reports.
The Russian Direct Investment Fund, which bankrolled the development of Sputnik V, said in November it will cost less than $10 per dose on international markets.
In turn, Syria released an Israeli citizen who entered the country illegally and Israel returned two Syrian shepherds that had entered the Israeli side of the Golan Heights, according to the reports.
The Syrian state news agency has denied the existence of such a deal.
The released Israeli woman returned to Israel via Moscow and was questioned by the Shin Bet domestic security agency.
The 25-year-old woman hails from the predominantly ultra-Orthodox settlement of Modi'in Ilit and had previously attempted to cross Israel's borders with the Gaza Strip and Jordan, according to the local media.
The woman reportedly crossed into Syrian territory from the Golan Heights, which Israel captured in the 1967 Six-Day War and annexed in 1981, a move not widely recognized internationally.
Her identity and motivation for crossing into Syria were not released by Israeli officials.
Gideon Saar, a former Netanyahu ally who is now running to unseat him in the March 23 elections, said Sunday that the government's "censorship of something that Damascus and Moscow know about, and Israeli citizens don't, is incomprehensible."
Israel and Syria remain in an official state of war and Israeli citizens are officially prohibited from visiting Syria. Israel has conducted hundreds of airstrikes on Iranian-linked targets in the country since the start of its civil war a decade ago.
Israel considers Iranian entrenchment on its northern frontier to be a red line and has repeatedly struck Iran-linked facilities and weapons convoys destined for Hezbollah.
At the same time that Israel has paid for Syria to receive COVID-19 vaccines, the government has refused to provide large quantities of vaccines to Palestinians in the West Bank and Gaza, drawing outcry from human rights organizations.
The disparities have drawn criticism from UN officials and rights groups, and have shined a light on the inequities between rich and poor countries getting access to vaccines.
These groups contend that Israel is responsible for vaccinating the Palestinians in the occupied territories. Israel has argued that under the Oslo Accords signed with the Palestinians in the 1990s, the Palestinian Authority must see to vaccinating its own population.