A luxury car dealer and three companions were kidnapped by gunmen outside a restaurant in the Mexican Caribbean resort city of Cancun, prosecutors said.

Geovany Gonzalez, his girlfriend, Thalia Rojas, personal trainer Alejandro Palafox and an unidentified employee were abducted last Friday, Quintana Roo state Deputy Attorney General Juan Ignacio Hernandez Mora said.

Officials did not confirm the kidnapping until Monday because the family has not officially reported the crime to authorities, Hernandez Mora said.

Authorities are monitoring the situation but their actions are limited because the crime has not been officially reported, the deputy state AG told Enfoque Radio.

"I had contact with people close to Geovany Gonzalez on Friday night, (and) we suggested they file a complaint," Hernandez Mora said.

"The kidnapping targeted Geovany Gonzalez because his relatives were the ones from whom ransom was demanded," Hernandez Mora said.

"The sum being demanded is exorbitant, but that is how the negotiation process in these cases normally starts. We know he is in the automobile business, but we do not have any other information," the deputy state AG said.

Palafox is a partner in a gym and works as a personal trainer for local businessmen, Hernandez Mora said.

Police working on a tip found an abandoned SUV Monday that contained four cell phones belonging to the victims and 33,000 pesos (about $2,500) in cash.

The victims were kidnapped after leaving a restaurant located a short distance from where the vehicle, whose sides were damaged, was found.

Kidnapping has become a widespread problem in Mexico in recent years, with gangs of different levels of sophistication targeting victims from various strata of society.

In October 2010, Congress approved a bill that stiffens the penalties for kidnappers from 25 to 45 years behind bars when the victims are mutilated or if the criminals are retired or active-duty police officers, and from 40 to 70 years in prison if the victims are killed.