Sources close to the UFC confirmed to the Review-Journal information first reported by ESPN.com on Tuesday.
Now that the original findings have been backed up, the adjudication process can move forward between USADA and the UFC light heavyweight champion.
The sample was collected the night before Jones won back the belt with a third-round knockout of Daniel Cormier in the main event of UFC 214 in Anaheim, California.
The development does not come as a surprise as ‘B’ samples almost invariably confirm the findings of the ‘A’ sample.
A blood test conducted on the night of the fight has come back clean, but was not screened for the same substances.
Jones, who will likely go before an arbitrator to decide his fate on the latest infraction, faces a potential ban of up to four years for his second violation of the UFC’s anti-doping policy, which is administered by USADA.
He was previously suspended one year when he was found negligent after testing positive for two estrogen blockers, which he argued were found in a tainted sexual enhancement pill he had received from a friend.
Jones, 30, was first stripped of the title as a result of several legal issues, including a hit-and-run accident in Albuquerque, New Mexico.
It is very possible UFC officials will again take the belt away from Jones, though no determination has been made at this point.
The California State Athletic Commission, which also has jurisdiction on the matter, has yet to move forward with its case. Jones’ win over Cormier will almost certainly be overturned to a no-contest.
Representatives for Jones have publicly maintained his innocence. Their investigation has already begun into how the substance could have entered his system.
Jones did pass several out-of-competition tests leading up to the fight with Cormier, including two in early July.
The adjudication process could last several months.
Contact Adam Hill at firstname.lastname@example.org or 702-277-8028. Follow @adamhilllvrj on Twitter.