US immigration agents have arrested famed Mexican boxer Julio Cesar Chavez Jr, 39, and plan to deport him to Mexico, where he has "an active arrest warrant... for his involvement in organised crime", US officials announced on Thursday.

Less than a week before his arrest, the former middleweight world champion was defeated by influencer-turned-boxer Jake Paul at a match in California.

US officials say he is affiliated with the notorious Mexican Sinaloa drug cartel. His lawyer denied the claims.

"Under President Trump, no one is above the law - including world-famous athletes," a spokeswoman for the Department of Homeland Security (DHS) said in a statement following his arrest.

Chavez Jr was arrested by Immigration and Customs Enforcement (ICE) officers in Studio City, Los Angeles, on Thursday.

His fight against Paul was in nearby Anaheim on Saturday. Chavez Jr is the son of former boxing champion Julio Cesar Chavez Sr, who is considered to be the best boxer in Mexico's history.

The DHS statement said that the "prominent Mexican boxer and criminal illegal alien" is being processed for "expedited removal".

"Chavez is a Mexican citizen who has an active arrest warrant in Mexico for his involvement in organised crime and trafficking firearms, ammunition, and explosives," the statement said.

It added that officials believe that he may be affiliated with the Sinaloa Cartel, which President Donald Trump designated as a terrorist organisation on his first day back in office in January.

Describing the alleged connection, the statement says he applied for US permanent residency last year due to his marriage to a US citizen "who is connected to the Sinaloa Cartel through a prior relationship with the now-deceased son of the infamous cartel leader Joaquin 'El Chapo' Guzman".

According to US officials, Chavez Jr has been arrested and jailed for several offences in the US, many involving weapons.

In January 2024, he was arrested and later convicted for illegal possession of an assault weapon, officials said.

In 2023, a local judge in the US issued an arrest warrant against him for allegedly trafficking weapons for a criminal organisation.

Nearly a decade earlier, in 2012, he was arrested for driving without a license under the influence of drugs or alcohol.

He also allegedly made multiple fraudulent statements to US immigration authorities in his attempts to gain permanent residency and over-stayed a tourist visa that expired last February.

A lawyer for Chavez Jr called his arrest "nothing more than another headline to terrorise the Latin community".

Asked about the allegations of a cartel connection, lawyer Michael Goldstein told NBC: "This is the first we've ever heard of these outrageous allegations."

Two weeks before the bout against Paul, Chavez Jr held a public workout in LA where he spoke to the LA Times about the massive uptick in immigration raids that have swept the city in the past month.

He said that his own trainer was afraid to come to work, due to fear of deportation.

"I was even scared to tell you the truth. It's very ugly," he said, accusing US immigration agents of "giving the community an example of violence".

"I'm from Sinaloa, where things are really ugly, and to come here, to such a beautiful country with everything... and see Trump attacking immigrants, Latinos, for no reason. Not being with God makes you think you know everything. Trump made a bad decision."

He added: "After everything that's happened, I wouldn't want to be deported."