LOS ANGELES, Calif. (AP) — A federal judge on Tuesday dismissed part of a lawsuit that alleged the FBI violated the civil rights of Muslims in Southern California when the agency hired an undercover informant to infiltrate mosques.

U.S. District Judge Corman J. Carney made the decision in the case against the FBI, saying that though the federal agency has immunity, it doesn’t apply to seven federal agents named in the suit.

The American Civil Liberties Union of Southern California and the Council on American-Islamic Relations jointly filed the suit last year.

“We don’t believe the Constitution permits (Carney’s) conclusion and as a result of the court’s decision, hundreds of law-abiding Muslims in Southern California will never learn whether the government violated their most basic civil rights,” said Ahilan Arulanantham, an ACLU attorney.

The civil liberties group has vowed to appeal.

The key informant in the case, civilian Craig Monteilh, turned against the FBI and described how the agency taught him to ingratiate himself into the religious community to secretly gather cellphone number and email addresses and to record conversations.