A United Nations panel has ruled that Mexico's 2013 arrest and continuing detention of a community police leader was illegal, raising hopes among her supporters she could be freed.

Nestora Salgado is a Seattle-area resident who returned to her native Mexico and led a vigilante-style — but legal — community police force, which mounted patrols to protect residents from cartel operatives.

Salgado was arrested in August 2013 after people detained by her group alleged they had been kidnapped.

The International Human Rights Clinic at Seattle University Law School took her case to the UN's Working Group on Arbitrary Detention. In a decision released this week, the five-member panel called her arrest arbitrary. The ruling is not binding on Mexico, but it could increase pressure to release her.