By Ian Simpson

(Reuters) - Maryland's attorney general has appealed a judge's order for a new trial for Adnan Syed, whose murder conviction was put into question by the 2014 podcast "Serial."

Syed, 36, is serving a life sentence for the 1999 murder of his former girlfriend, Hae Min Lee. His lawyers had sought a new trial amid questions about the case's fairness that the podcast raised in late 2014, and a Baltimore judge ordered the trial in June.

The appeal, filed in Baltimore City Circuit Court late on Monday, argued that Judge Martin Welch had wrongly allowed new arguments over cellphone evidence that linked Syed to Lee's death.

Syed should not be granted a new trial "when there has been no new evidence, no change in law, no material link to the

original justification for remand, and no reason why the claim could not have been raised at numerous prior proceedings," Deputy Attorney General Thiruvendran Vignarajah said in the 45-page appeal.

He also contested Welch's decision to vacate Syed's conviction because of ineffective legal help, saying Syed's lawyers had failed to raise the argument during his original appeal and in other petitions.

Lee's body was found buried in a Baltimore park. Syed was convicted in 2000 of murdering her and remains in prison pending the outcome of a new trial.

The "Serial" podcast on Syed's case was released by public radio station WBEZ in Chicago and has been downloaded tens of millions of times. The podcast raised questions about the case, including testimony from one of the witnesses and phone calls that linked Syed to the crime.

In his ruling, Welch said Syed's original lawyer, Cristina Gutierrez, had failed to cross-examine prosecutors' expert about the reliability of cellphone tower location evidence.

Syed's lawyers had argued that Gutierrez had failing skills when she defended him. She later was disbarred, and died in 2004.

(Reporting by Ian Simpson in Washington; Editing by Dan Grebler)