Former Tijuana mayor Jorge Hank Rhon has been released from police custody for a second time in the same day after a Mexican judge ruled there was not enough evidence to hold him.

Hank Rhon was detained by Mexican prosecutors Tuesday afternoon for questioning related to a murder investigation, just minutes after he had been released on separate charges related to illegal weapons.

The wealthy businessman was first arrested earlier this month after a raid on his house turned up 88 weapons and nearly 10,000 rounds of ammunition. Prosecutors have said that two of the guns were linked to two separate killings in 2009 and 2010.

Hank Rohn was mayor of Tijuana, across the border from San Diego, California, from 2004 to 2007.

He is the son of a prominent figure in the Institutional Revolutionary Party, which led Mexico for more than seven decades until 2000 and is trying to win back the presidency next year.

Hank Rohn also owns a chain of casinos and a local soccer team.

In 1999, a report by the U.S. National Drug Intelligence Center identified Hank Rhon as having links to drug trafficking, but then-U.S. Attorney General Janet Reno said the report's findings were never adopted as the official government view.

The former mayor, who also ran unsuccessfully for governor of Mexico's Baja California state, has denied allegations of corruption and ties to drug traffickers.