Mexican President Vicente Fox is deciding how best to change and strengthen his security forces and bodyguard protection, following the arrest of one of his senior staff members, who is accused of leaking his travel itinerary to a drug cartel.

The Mexican Attorney General's Office has confirmed that Nahum Acosta, the official in charge of organizing President Vicente Fox's frequent official trips around the country, is accused of leaking details of the president's travel agenda to drug traffickers in Northern Mexico. Acosta was arrested in the Presidential Palace last week. He has worked in the travel office since 2001, and was a trusted senior member of staff.

The Fox administration has arrested more drug cartel leaders than any previous government, following the president's campaign pledge to make the fight against narcotics traffickers his number one law and order priority.

?We will convince them that this is a real challenge for us, and we are going to win the battle against drug trafficking within Mexico,? said Mr. Fox.

Last month, President Fox again upped the stakes, cracking down even harder on the cartels. He ordered the Army and Federal Police to take over operation of several key maximum security penitentiaries and split up their most dangerous inmates, sending them into separate facilities.   He has also reinforced several beleaguered police forces on Mexico's border with the United States, where the cartels are particularly violent.

Professor Celia Toro, an expert on drug cartels, is based at the College of Mexico. She says a rash of drug-related killings is directly related to the government's stepped-up campaign to dismantle the drug cartels.

?The smuggling per se, or cocaine trafficking per se, doesn't bring any violence,? says Ms. Toro.  ?What brings violence is increasing enforcement against them. Violence is a reaction against more sophisticated or more powerful enforcement against them.?

Rolando Soliz spent 23 years in the U.S. Secret Service. During that time he was bodyguard to presidents Nixon, Ford, Carter, Reagan and Bush.  He is now the Director General of the Mexico City office of Vance International Security firm.

Mr. Soliz says the fact that a drug cartel was able to penetrate the inner circles of the president is a matter of great concern.

He says, while there are limits to the ability to keep the president's trips secret, the security apparatus must be tightened to make his travel safe.

?It's like moving around an 800 pound gorilla,? he explained.  ?Sooner or later, the public needs to know that he's coming to visit, or will know that he's coming to visit a certain site, because he doesn't travel just by himself. He's traveling with a large entourage.

President Fox himself is acknowledging he is under a greater threat.  He has called for redoubled vigilance, saying the conflict between the authorities and organized crime, has made the drug gangs challenge the Mexican state.