IT DIDN’T take long for Mexico’s ruling Institutional Revolutionary Party (PRI) to react to the seriousness of the sex scandal erupting around it on April 2nd. Just hours after Cuauhtémoc Gutiérrez de la Torre, the party’s president in Mexico City, publicly denied a report that he kept a network of prostitutes on the party payroll for his personal use, the PRI put him on leave and called for a police investigation. The story by MVS News, one of Mexico’s most influential radio programmes, is colourful and the allegations it makes are potentially very sordid. Mr Gutiérrez, as heavy-set as an ox, comes from a family that made a fortune on Mexico City’s rubbish tips. His murdered father (a former PRI stalwart) was known as the “King of Rubbish”. Heading the PRI in Mexico City is the highest office he has held, although the party has not ruled there since 1997. His office issued a statement saying the MVS report was “deceitful, ill-intentioned and slanderous” and that Mr Gutiérrez himself wanted an investigation.

According to MVS, the women at the heart of its report are known as edecanes, or hostesses. In their short skirts and high heels, they are a common feature of political and business gatherings in Mexico. Mostly their job is to hand out brochures or accompany people to their seats.

MVS said that after a tip-off, a female reporter answered an advertisement for a hostess job in Mr Gutiérrez’s office at PRI headquarters in Mexico City. It aired what it said were secretly taped recordings in which a woman it claims worked for Mr Gutiérrez can be heard telling the undercover reporter the job requires her to provide sex—“oral or vaginal”—when her boss asks for it, as well as more normal hostess duties. The tape recordings include discussion of salary—11,000 pesos ($850) a month, tax-free, plus tips—and the reporter is told she will be on the PRI’s payroll. “It’s absolute discretion, because obviously he protects his image,” the female voice tells the reporter.

Speaking on air to MVS News, Mr Gutiérrez described the report as “false as all falseness” and said there were no hostesses on the PRI payroll. He was not asked whether the woman on the tape was his employee.

The scandal immediately lit up the airwaves and social-media sites. It puts the PRI in an awkward spot. The party, which ruled Mexico for much of the 20th century, often according to rules it set for itself, returned to power nationwide in 2012 with the election of President Enrique Peña Nieto. It is keen to put its sleazy past behind it. But given the murky relationship between politics and justice in Mexico, investigations often lack credibility. People believe what they choose.