Junior welterweight champion Lamont Peterson has reportedly tested positive for synthetic testosterone, according to Steve Carp of the Las Vegas Review-Journal.

The upcoming HBO-televised defense of his WBA/IBF 140-pound titles against Amir Khan on May 19th at the Mandalay Bay in Las Vegas, is now in jeopardy. Khan and Peterson had agreed, as part of their rematch terms, to take part in a random drug testing protocol.

"Peterson was found to have synthetic testosterone in his system according to tests conducted by VADA in March," Carp said on Twitter on Monday night, citing the drug-testing agency.

Carp said VADA head Margaret Goodman declined to comment on the test, but he noted that "VADA has dropped Peterson from its client list."

"Peterson took a random drug test in mid-March that came back positive," Carp reported. "The 'B' sample was tested at the end of April, also yielding a positive result."

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