Prosecutors say the abductions are linked to a dispute between two rival drug gangs, one in Mexico City’s dangerous Tepito neighbourhood, home to most of the abducted. The families of the disappeared, however, say they were not involved in drug trafficking.

Surveillance cameras showed several cars pulling up to Bar Heaven and taking the victims away. A witness who escaped the kidnapping told authorities that a bar manager had ordered the music turned off, told patrons that authorities were about to raid the establishment and ordered those inside to leave.

The cameras showed most of the 12 getting into cars outside and being taken away.

They have not been heard from since.

So far, six people have been arrested in the Heaven case, including club owner Ernesto Espinosa Lobo, known as “The Wolf,” who has been charged with kidnapping. Among the arrested are another bar owner, a driver and security guard.

One suspect is still a fugitive.

The bizarre disappearance resonated across the city of nine million because many had come to believe it was an oasis from Mexico’s cartels and drug violence.

A mass abduction of 12 mirrors crimes in drug-trafficking hot spots such as the western state of Michoacan, where 21 tourists disappeared, only to be found in a mass grave, or in Monterrey, where 17 kidnapped musicians were found dead in the bottom of a well.

City officials have insisted since the Heaven kidnapping that large drug cartels do not operate in the city. But the case has been a political liability, with local polls showing the public overwhelmingly opposed to how Miguel Mancera, the Mexico City mayor, has handled the case.

In another element of the case that is reminiscent of drug gang warfare, one of the owners of the Heaven bar, Dax Rodriguez Ledezma, fled authorities only to turn up dead, his body dumped and burned in a rural area with that of his girlfriend and another friend.

Ricardo Martinez, an attorney for relatives of the missing, told The Associated Press earlier that state and federal officials had informed him that 13 bodies had been found on a ranch east of Mexico City. He said officials suspected they belonged to those who disappeared from the bar.

Mr Martinez said a suspect in the Heaven case led officials to two graves containing the bodies. He said he was told there are 13 bodies because the family of one of the disappeared never reported the person missing.

Edited by Bruno Waterfield for telegraph.co.uk