Mexican security forces have arrested the wife of "El Mencho", Mexico's most wanted man and the leader of the feared Jalisco New Generation Cartel (CJNG).
Rosalinda González is suspected of running the CJNG's finances.
Mexico's defence ministry said she was arrested in Zapopán, the same city where she was detained in 2018.
She had been released on bail while awaiting trial on money laundering charges after paying 1.5m pesos ($78,000; £58,000).
Her husband, whose real name is Nemesio Oseguera Cervantes, has been on the run for years.
The US Drug Enforcement Administration is offering a $10m (£7.2m) reward for information leading to his capture.
The CJNG is one of the most powerful drug cartels in Mexico and has been behind some of the deadliest attacks on Mexican security forces, such as a 2015 ambush in Jalisco which left 15 officers dead.
It has spread from its original power base in the state of Jalisco to have an almost nationwide presence.
Security officials say the group was also behind the brazen assassination attempt on Mexico City's police chief, Omar García Harfuch, last year.
In a separate development on Tuesday, two Mexican Marines were abducted in Zapopán and the government was concerned this was linked to the arrest of Ms González, a Mexican official was quoted as saying by Reuters.
Ms Gonzalez and her husband have three children, among them Rubén Oseguera González, known as "Menchito" (Little Mencho), who was extradited to the United States on drug trafficking charges in 2020.
The cartel is believed to have further stepped up its attacks on the security forces in retaliation for Menchito's extradition.
Earlier this year, police blamed it for drone attacks on their officers.