Hezbollah is fighting in Syria with American weapon systems supplied by the United States to the Lebanese Army, a senior Israel Defense Forces officer speaking under conditions of anonymity said Wednesday.

According to the officer, Israel has supplied the U.S. administration with evidence, including photographs, of American-supplied armored personnel carriers being used by Hezbollah in Syria.

The senior officer added that while it is not clear under which circumstances Hezbollah obtained the American APC’s from the Lebanese Armed Forces, he believed that it was part of “a deal” and that Hezbollah has recently “strengthened its grip on the main national institutions in Lebanon,” including its army.

Lebanon is currently the fifth-highest recipient of U.S. military aid in the form of light and medium weapons and armored vehicles, supplied by the Obama administration in order to help the Lebanese fight Islamist terror organizations. This includes M-113 APC’s and M-60 tanks. The latest shipment in August was worth an estimated $50 million and included 50 new APCs and 40 artillery pieces.

According to the officer, “Israel wants to see Lebanon flourish and believes that it needs an army but doesn’t want to see Hezbollah play a major role in it.” Israeli intelligence believes that cooperation between the LAF and Hezbollah has reached a level whereby the two forces patrol together on the Israel-Lebanon border and Hezbollah directs the LAF where to build its new observation posts on the border and shares in the intelligence collected.

In recent weeks, Israel has obtained evidence of some of the U.S.-supplied APCs being used by Hezbollah on the battlefield in Syria. Hezbollah has been fighting for most of the last six years alongside the Assad regime and Iran’s Islamic Revolutionary Guards Corps in Syria and has lost by now over 1,700 of its fighters. The evidence was passed on the U.S. through the standard intelligence cooperation channels and it is not clear yet whether the administration has acted upon it with the Lebanese government.

Open gallery view File photo: Lebanese soldiers on U.S.-made M-60 tanks. Credit: AP

Earlier in December, Defense Minister Avigdor Lieberman said that although "Israel has no intention of intervening in the civil war in Syria," it would not allow chemical weapons to reach Hezbollah in Lebanon.

Speaking a day after Israel's second reported attack in Syria, the defense minister said that "Israel's policy is clear and based on three red lines: We won't allow any harm to come to our citizens, we won't allow our sovereignty to be infringed on and we will not allow advanced weapons or chemical weapons from Syria to be smuggled to Lebanon for Hezbollah."

In a possible reference to Russian presence in Syria, Lieberman asked to clarify that Israel acts "freely" in the area "without taking into account the circumstances or other restrictions."

A week earlier, Syria said that Israeli jets attacked west of Damascus, with reports in Arab media saying an arms convoy intended for Hezbollah was the target. The news came amid tensions along Israel's northern border after clashes between the Israeli army and militants affiliated with the Islamic State group.