MEXICO CITY (AP) -- Mexico's National Human Rights Commission is urging prosecutors to protect a Texas-based norteno singer who was detained at a Christmas party held by a reputed drug cartel.

In a statement Sunday, the commission says it acted after authorities received worried phone calls from Ramon Ayala's wife and lawyer expressing concern over his detention during a military raid Dec. 11.

Ayala's lawyer says the singer and his band didn't know they were hired by drug suspects.

The party was supposedly thrown by the Beltran Leyva cartel, whose leader, Arturo Beltran Leyva, was killed in a shootout with marines five days later.

No formal charges have been filed against Ayala, a Mexican accordionist who lives in Hidalgo, Texas.

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