Authorities in Mexico have launched a criminal investigation regarding the disappearance of three Italian men, in which four police officers stand accused of handing the men over to criminal conglomerates running opioids, methamphetamine and other illegal substances known as 'cartels.'

All the missing Italians were from Naples and disappeared on January 31 in Tecalitlán, in the western state of Jalisco.

The state governor said that the four Mexican officers confessed to handing the Italians over to the local cartel after having arrested them at a petrol station beforehand.

The three Italians, Raffaele Russo, 60, his 25-year-old son Antonio, and his nephew, Vincenzo Cimmino, 29, had stopped at a petrol station in Tecalitlán, an agricultural town.

The last the men were heard from was a via a WatsApp message from Raffaele Russo, telling family members back in Italy that police officers had just approached them and they had been ordered to follow them.

The local cartel controlling the region, the Jalisco New Generation, is also one of the most powerful in the entire country.

Mexican authorities have said that an additional three police officers are wanted in relation to the disappearance.

There are also rumours surfacing in Mexican local media that the town's police force was sent for "retraining" for the purposes of not being intimidated by the local cartel members into changing their stories.

However Jalisco State Prosecutor Raúl Sánchez said that he had information that shows the men were trying to sell 'cheap generators and agricultural machinery' which they told people was of good quality, however their relatives back in Italy denied knowing anything like this.

Mexican media have parallelized the case with that of the disappearance of 43 Mexican students from the town of Iguala in 2014.

Back then, the students were handed out to another criminal gang by corrupt police members. The students were killed and their bodies were burned.

Local police are poorly trained and poorly paid, making them turn a blind eye to many activities by the very powerful criminal organizations, prompting the federal government to send in army troops at very difficult cases.