The wife of jailed Mexican drug lord Joaquín "El Chapo" Guzmán has been arrested in the US on suspicion of drug trafficking, US authorities say.
Emma Coronel Aispuro, 31, was detained at Dulles International Airport outside Washington DC.
She is charged with participating in a conspiracy to distribute heroin, cocaine, methamphetamine and marijuana.
Guzmán is currently serving a life sentence in Colorado for drug trafficking and money laundering.
The 63-year-old is a former head of the Sinaloa cartel, which officials say was the biggest supplier of drugs to the US.
His trial in 2019 heard shocking revelations about his life, from drugging and raping girls as young as 13 to carrying out the cold-blooded murders of former cartel members and rivals.
Ms Coronel Aispuro appeared via video link before a federal judge at a court in Washington DC on Tuesday and was ordered to remain in detention for the time being.
Prosecutor Anthony Nardozzi said Ms Coronel Aispuro had "worked closely" with members of the Sinaloa cartel and had possessed the "financial means to generate a serious risk of flight".
As well as facing drug trafficking charges, she is also accused of conspiring with others to help her husband escape from prison in Mexico in 2015.
He was sprung from Mexico's maximum-security Altiplano prison after his sons bought a property near the prison and a GPS watch smuggled into the prison gave diggers his exact location. He escaped by riding a specially adapted small motorcycle through the tunnel.
Court documents said Ms Coronel Aispuro was allegedly involved in planning another prison escape for her husband before he was extradited to the US in January 2017.
She has not commented on the charges.
Mexican President Andrés Manuel López Obrador said the arrest was "a matter that the United States will decide" but added that he hoped the US would share more of the details.
Who is Emma Coronel Aispuro?
Ms Coronel Aispuro is a dual US-Mexico citizen, a former beauty pageant winner and journalism student, and the mother of twins with Guzmán. According to previous interviews gave to US media, she first met Guzmán at a dance when she was 17 and he was 49.
She attended nearly every day of her husband's three-month trial in New York, during which she heard not only grim accounts of murder and rape, but also claims he had spied on her and other mistresses.
She came under the media spotlight during that trial. In one instance, she appeared to laugh during the tearful testimony of one of Guzmán's mistresses. On another day she and Guzmán wore similar velvet jackets, which many people interpreted as a show of solidarity.
She remained supportive of Guzmán throughout, saying at the end of the trial: "I don't know my husband as the person they are trying to show him as, but rather I admire him as the human being that I met, and the one that I married."
Guzmán came from a poor family in Sinaloa state, north-west Mexico. His organised crime business grew so big that he entered Forbes' 2009 list of the world's richest men at number 701, with an estimated worth of $1bn (£709m).