The Wall Street Journal wrote that Amman has allowed the arms funded by Saudi Arabia and Qatar to be transferred across the Jordanian border with Syria.
"Several shipments of arms have been delivered to the border in Jordanian military trucks and then taken into Syria by rebel brigades. The weapons included assault rifles, Russian-designed antitank missiles and ammunition," the newspaper quoted terrorists as saying in an article published on Friday.
It cited gunmen based along the Syria-Jordan border and a person involved in arms procurement for the terrorists as saying that "Saudi Arabia and Qatar pay for these arms and transport them to Jordan".
The Wall Street Journal noted that "such an energized supply route through Jordan would show how even regional states with the risk of significant blowback" are boosting support for the terrorist groups in Syria "with the tacit backing of Western allies".
The newspaper quoted officials in the region as saying that Jordan has boosted ties with more leaders of terrorist groups in Syria's southern cities near its border, which helped facilitate transfer of funds and arms to the terrorist groups.
The Kingdom's growing involvement with the activities of Syrian rebels was outlined by six rebel officers and opposition politicians, two of which are directly involved in the procurement or transfer of arms into Syria, it said.
It pointed out that several of the terrorist groups' members say they had met with Jordanian officials, and that a non-Jordanian Arab official "confirmed the characterization of the kingdom's role."
The article highlighted the court of the Jordanian king, who sets military and security policy, didn't respond to written questions about stepped-up political or military assistance, nor did Jordan's foreign ministry or prime minister's office.
"Jordanian intelligence officials routinely host meetings with these so-called Free Syrian Army leaders, helping facilitate their movement back and forth from Syria and discussing military strategy," the daily quoted people familiar with the meetings as saying.
"Some of the weapons which entered Syria through Jordan were destined for the southern Syrian border city of Daraa, while most of the arms were pushed North to the suburbs of Damascus, 60 miles North," it cited some terrorist leaders as saying.
Other gunmen stressed that Daraa "remains one of the last supply routes" to the terrorists in the capital, with "pathways from the Turkish border and around Homs too risky".