Adnan Syed, the subject of last year's popular "Serial" podcast, may be due for a re-trial following the revelation that evidence used to send him to jail should have been excluded from the trial.

Syed is currently serving a life sentence for the murder of his ex-girlfriend, Hae Min Lee, who was found strangled to death and buried in a Baltimore car park in 1999, according to The Week.

Incoming call data was used to place Syed at the scene of the crime when it occurred, but yesterday his lawyer C. Justin Brown filed a court motion claiming that AT&T, the service provider for Syed's phone, had warned police about relying on its accuracy.

The message that AT&T sent to Baltimore Police specifically said that "outgoing calls only are reliable for location status. Any incoming calls will NOT be considered reliable information for location," according to People.

Brown noted if that warning had been "properly raised at trial" by Syed's previous defense attorney, Cristina Gutierrez, "much of, if not all of, the cellular evidence would have been rendered inadmissible."

"If AT&T, the architect and operator of the cell tower network, did not think incoming calls were 'reliable information for location,' it is unfathomable that a Baltimore City Circuit Court judge would have allowed an expert opinion...under this method," Brown wrote in the motion.

Brown told The Baltimore Sun, "We feel that the fax cover sheet from AT&T is an extremely important piece of evidence, and we are bringing it to the court's attention as quickly as possible. We hope the court considers it."

News of the AT&T cover sheet is the second instance of Syed's current legal representation claiming he had been given "ineffective assistance" by Gutierrez. Syed's defense also notes Gutierrez failed to interview Asia McClain, a potential witness who reported seeing Syed at Woodlawn High School around the time of the murder.

The Maryland attorney general's office has made no comment about these developments.