By Veronica Gomez and Dave Graham

MEXICO CITY (Reuters) - Mexico recaptured the world's most notorious drug lord Joaquin "El Chapo" Guzman with U.S. help in a violent standoff on Friday, six months after he humiliated President Enrique Pena Nieto with a jaw-dropping escape from a maximum security prison.

The head of the powerful Sinaloa Cartel, who Pena Nieto first caught in February 2014, was captured at a roadside motel after an early morning operation that killed five in the city of Los Mochis in the drug baron's native northwestern state of Sinaloa.

"Mission accomplished: We have him," Pena Nieto said on his Twitter account. "I want to inform all Mexicans that Joaquin Guzman Loera has been arrested."

For Pena Nieto, the capture of a trafficker who twice slipped out of Mexican prisons is a sorely-needed victory after his presidency was tarnished by graft and human rights scandals and the shame of the kingpin's July flight.

It also provides a major boost for U.S.-Mexico relations, strained by the apparent ease with which Guzman gave Mexican authorities the slip after the United States requested his extradition.

Once featured in the Forbes list of billionaires, Guzman has led a cartel that smuggled billions of dollars worth of cocaine, heroin, marijuana and methamphetamines into the United States and fought vicious turf wars with other Mexican gangs.

Scant official details were available of the recapture, but it involved Mexican marines, the U.S. Drug Enforcement Administration (DEA) and U.S. Marshals, a senior Mexican police source said.

The source said Guzman was captured from the Hotel Doux, a motel on the outskirts of Los Mochis once popular with North Americans traveling south. It was the result of a deadly operation announced earlier on Friday by the Mexican Navy in which five others were captured.

One photograph widely circulated on social media, but that could not be independently verified by Reuters, appeared to show Guzman sitting handcuffed on a hotel bed, in a room that resembled those shown on the Hotel Doux website. He was wearing a filthy vest and a poster of a scantily clad woman was pinned on the wall behind him.

Story continues

A receptionist at the motel told Reuters she understood Guzman had been captured there.

Another photo appeared to show Guzman without handcuffs and wearing the same vest in the back of vehicle next to one of his top assassins.

The DEA, which has had a bumpy relationship with its Mexican counterparts, congratulated Mexico on the capture.

"This notorious criminal is – and will remain – behind bars, until he faces justice in a court of law," said DEA Acting Administrator Chuck Rosenberg.

EXTRADITION WILL 'TAKE TIME'

Guzman now faces the prospect of extradition to the United States. After coming under fire for failing to do so the last time, Mexico's Attorney General's office said in July it had approved an order to extradite him north of the border.

On Friday, the U.S. Justice department said its previous request to extradite Guzman to the United States still stands and U.S. Attorney General Loretta Lynch said the kingpin will have to answer for his alleged crimes.

In a celebratory speech in his ceremonial palace, Pena Nieto said the capture was the result of months of work by Mexican intelligence and security agencies and the attorney general's office. He did not mention U.S. assistance.

Guzman's jail break in July, when he escaped through a mile-long tunnel which burrowed right up into his cell, capitalized on the drug-tunneling techniques he honed on the U.S. border.

His flight heaped embarrassment on Pena Nieto, who had resisted the U.S. request to extradite and had said previously that an escape would be "unforgivable."

Dozens of people were arrested over the jail break, though details of who Guzman bribed and how his accomplices knew exactly where to tunnel into the prison remain scarce.

Guzman is wanted by U.S. authorities for various criminal charges including cocaine smuggling and money laundering. An official at the attorney general's office, speaking on condition of anonymity, said his extradition would "take time".

Guzman's lawyer in October appealed against possible extradition in case his client was captured.

'A SURVIVOR'

Guzman was born in La Tuna, a village in the Sierra Madre mountains in Sinaloa state where smugglers have been growing opium and marijuana since the early 20th century.

In 1993, police arrested him in Guatemala and extradited him to Mexico. Guzman used money to ease his eight year prison stay, smuggling in lovers, prostitutes and Viagra, according to international and domestic media reports.

The kingpin's legendary reputation in the Mexican underworld began to grow in 2001, when he staged his first jail break, bribing guards in a prison in western Mexico, before going on to dominate drug trafficking along much of the Rio Grande.

Still, many people in towns and villages across Mexico remember Guzman better for his squads of armed gunmen who carried out thousands of brutal slayings and kidnappings.

After Guzman's first prison break, violence began to creep up in Mexico and the situation deteriorated during the 2006-2012 rule of Pena Nieto's predecessor Felipe Calderon, when nearly 70,000 people lost their lives in gang-related mayhem.

Guzman's reputation grew and in 2013 Chicago dubbed him its first Public Enemy No.1 since Al Capone.

El Chapo, or "Shorty", is believed to be 58 years old. The 5-foot, 6-inch gangster's exploits made him a hero to many poor villagers in and around Sinaloa, where he was immortalized in dozens of ballads and low budget movies.

Security experts concede Guzman has been a master of his trade, managing to outmaneuver, outfight or outbribe his rivals to stay at the top of the business for over a decade.

"El Chapo Guzman is a survivor," Anabel Hernandez, author of Narcoland: The Mexican Drug Lords and their Godfathers, said shortly after his July jailbreak.

(With reporting by Gabriel Stargardter, Christine Murray and Cyntia Barrera; Writing by Frank Jack Daniel; Editing by Simon Gardner and Mary Milliken)