LOS ANGELES — A federal judge ordered the Los Angeles Times to remove information from a published article Saturday, a step legal experts said was extremely unusual and conflicted with the First Amendment. The newspaper said it was appealing the order.

The article, published Saturday morning, described a plea agreement between prosecutors and a police narcotics detective in Glendale, California, who was accused of colluding with a Mexican crime syndicate.

The detective, John Saro Balian, 45, pleaded guilty Thursday to federal charges that he had accepted a bribe, obstructed justice and lied to federal investigators about his involvement with organized crime. U.S. District Judge John Walter ordered the plea agreement sealed, but a reporter found it posted online Friday in a public database of federal court documents.

Before the article was published, a lawyer for Balian told editors at the newspaper that doing so would put his family at risk. The newspaper decided to publish, and a few hours later, it received the court’s order. By 5 p.m. Saturday, it had complied by removing any references from the sealed document, although the article still made clear there had been a plea agreement with federal prosecutors.

The Times said it chose to abide by the order while it appealed, rather than risk being held in contempt of court.

“There is sort of (a) constant effort to nibble away at the First Amendment, and I think there is an obligation to respond to that and push back,” said Norman Pearlstine, the paper’s executive editor. “Once it’s out in the public record, it is our decision to decide whether it is newsworthy and we should publish.

“Ultimately, we will get the information out,” he added.

The judge sealed the motion, filed by Balian’s lawyer, that requested the order to the newspaper, so it was not clear on what basis it was sought or justified.

Balian’s lawyer declined to comment.