AP

AUSTIN, Texas (AP) — A man accused in an alleged scheme to buy and train racehorses to benefit the Zetas drug cartel was ordered detained Tuesday in Texas after a judge suggested he might flee to Mexico if released.

Jose Trevino Morales, the brother of two alleged cartel leaders, is among 15 people charged in what federal prosecutors said was a money-laundering scheme centered on an Oklahoma horse ranch. Authorities said Trevino was involved in an operation that quietly arranged to spend millions of dollars of drug money on racehorses.

But Trevino’s supporters argued that he was the innocent brother of two men — Miguel Angel and Oscar Omar Trevino Morales — reputedly near the top of the notorious Zetas cartel based in Mexico.

Jose Trevino pleaded not guilty at a Tuesday detention hearing in Austin. The Austin American-Statesman reported that his attorney, David Finn, argued that his client wasn’t a risk to flee or commit a crime. U.S. Magistrate Judge Mark Lane agreed that there was no evidence to suggest Trevino was a risk to the community, but he thought Trevino might flee to Mexico if he was let out of jail.

‘‘We’re disappointed with the magistrate’s decision,’’ Finn told The Associated Press after the hearing. ‘‘The government agreed that he is not a danger to the community or to society.’’

A spokesman for prosecutors did not return a phone message from the AP late Tuesday.

An Internal Revenue Service investigator who testified Tuesday said a federal informant — a drug distributor working for the Zetas — met Trevino several times when he secretly crossed the border for meetings with his brothers.