LAGOS (Reuters) – Nigerian immigration officials returned the passport of a prominent activist against police brutality after it was seized when she tried to leave the country last week, the activist said on Monday.

Thousands of people took to the streets last month in anti-police protests. The demonstrations climaxed on Oct. 20 when security forces opened fire and killed at least 12 protesters in Lagos, according to witnesses and Amnesty International. The army and police have denied the killings.

Modupe Odele, a lawyer who has helped arrange legal defence for the protesters, said last Wednesday she had tried to board an international flight in Lagos when immigration authorities told her she was under military investigation and barred from leaving Nigeria, seizing her passport.

On Monday, she told Reuters immigration officials returning the passport did not give her new details.

“I’m a little heartbroken that this happened because I was providing pro bono legal aid to peaceful protesters who were unlawfully detained,” Odele said. “I’m also grateful that this didn’t turn out worse.”

The immigration service did not respond to requests for comment.

(Reporting by Libby George, Tife Owolabi and Camillus Eboh; Writing by Paul Carsten; Editing by Angus MacSwan)