Clarkson meets his match: Mexico's man in London is a 24/7 crimefighter

Far from snoring in front of the TV, the ambassador is on constant alert after taking on the drug cartels back home. As Joanna Moorhead reveals, he was sent here for his own safety

It was Jeremy Clarkson's version of several rounds from a machine-gun. The victim was Mexico, whose food, he and his fellow Top Gear presenters chortled, was "refried sick". Its people were "lazy and feckless". Even the ambassador got it in the neck. There was no danger from him, said the portly, controversial broadcaster: "At the Mexican embassy, the ambassador is going to be sitting there with a remote control like this [snores]. They won't complain; it's fine."

Just one problem, Clarkson. That's not Eduardo Medina-Mora Icaza's style. He is, in fact, a one-man crime-fighting machine who headed Mexico's secret service before taking on his country's notorious drugs barons – and he was moved across the Atlantic to reduce the chance of him becoming a victim of the narcotic chiefs' assassins.

"It's so far from the truth that it's laughable," says a friend of his this weekend, speaking by phone from Mexico City. "Mr Clarkson is certainly ignorant about Eduardo... but I don't think Eduardo will be bothered by him. He's been up against much more dangerous enemies!

"In fact, if there's one man who's going to stay awake in the whole of Mexico, it's going to be Eduardo.

"He's had to spend the past few years of his life looking constantly over his shoulder... he's in danger the whole time, and he knows it. It's safer for him now he's in the UK, but once you've taken on the cartels, you're never going to be entirely 'safe'. He's one of the bravest, and most switched-on, people imaginable."

This weekend, officials at the Mexican embassy preferred to keep a dignified silence amid more mud-slinging from the embattled Top Gear presenter. In his Sun column yesterday, Clarkson said the remarks he and his fellow presenters Richard Hammond and James May made earlier this week – joking that Mexican cars reflected a national tendency to be "lazy, feckless, flatulent [and] overweight" – were "accidental".

Clearly still unaware of the distinguished track record of Mr Medina-Mora Icaza, Clarkson said: "If he was asleep, someone plainly woke him up, because he did complain and, in doing so, he seems to have started an international incident."

Clarkson went on to apologise for his remarks, but accused the Mexicans of being "humourless". However, in Top Gear terms, the Mexican embassy seems to have won – not only has the BBC itself, as well as Clarkson, had to offer an apology, but in tomorrow's programme, Mexico is being seen as "off limits" and is unlikely to get a mention.

"Clarkson didn't realise who he was taking on," says Mr Medina-Mora Icaza's friend. Nor did he reckon with the popular response from Mexico. Because, however lazy and feckless Clarkson might have thought they are, many Mexicans leapt to their country's defence; at times last week, Twitter was carrying up to 200 new tweets from the country every minute.

And it was the personal reference to Mr Medina-Mora Icaza which prompted many to act. He's a nationally respected figure, who graduated in law from university in Mexico City and went on to become one of his country's leading businessmen before being appointed head of the Centre for Research and National Security from 2000 to 2005. He was then appointed minister for public safety in the government of President Vicente Fox, and the following year he was promoted to attorney-general in the new government of President Felipe Calderon. His new brief: to tackle the increasingly bloody issue of organised crime, and drug-trafficking in particular, in Mexico.

The drugs war, which has claimed more than 35,000 lives over the past four years, affects Mexico's economy, its international relations and its tourism. Most of all, though, it affects its people – the security situation has deteriorated in the past few years, making life dangerous and frightening for millions of ordinary Mexicans.

Mr Medina-Mora Icaza was seen as the man who was determined to root out organised crime by tackling it in a way that he, as a successful businessman himself, understood. "He always used to say that to combat the cartels, he had to strangle their ability to reproduce their model both in time, and in geography," says his friend.

"In other words, what he meant was that these people are businessmen – and if you're going to bankrupt their business, you have to stop them from expanding. He saw their money-laundering operations as one very important area to tackle. And another thing he did was to spearhead a closer partnership with other countries, especially the US – and this was seen as a very important way forward in the war on drugs in our country."

Mr Medina-Mora Icaza was also instrumental in one of Mexico's highest-profile crackdowns on the drugs gangs when he ordered soldiers and armed federal police into the border town of Ciudad Juarez in March 2009 after the "narco insurgency" seemed to threaten the whole nation. "He took a tough line, he didn't allow himself to be cowed, and he stood firm against the cartels," says his friend.

And when it was discovered that his own office had been infiltrated by the cartels, Mr Medina-Mora Icaza left no stone unturned when he ordered a major clean-up operation that led to more than 200 officials – including his own second-in-command – being jailed.

"This is a not a man who is ever asleep on the job," says his friend. "In fact, he's a 24/7 worker."

Mr Medina-Mora Icaza resigned from his post as attorney-general in September 2009, saying that his work had come to an end. Friends, however, say the ever-present dangers of his role were becoming too much – he and his wife have three teenage children. His appointment to London was widely seen in Mexico City as a way of allowing him to have a life that didn't involve such heavy security. "He will always be at risk, but being in the UK means he and his family can lead a more normal life," says his friend.