A small-town Mexican mayor known for speaking out against drug gangs has been found dead on a roadside.

The director of the Association of Local Authorities of Mexico said on Friday that Ygnacio Lopez Mendoza, the mayor of Santa Ana Maya in the western state of Michoacan, had been abducted, tortured and killed. His body was discovered in his truck in the neighbouring state of Guanajuato.

Michoacan has been dominated for years by the Knights Templar drug cartel. Its members routinely extort money from residents, businesses and even local officials.

Former president Felipe Calderon published tweets demanding an explanation of the death of Mr Lopez Mendoza. "The mayor … was on a hunger strike in front of the Senate complaining of complicity between local police and criminals. Today he's dead. How did it happen?" Mr Calderon asked on Twitter.

The Association of Local Authorities said Mr

Lopez Mendoza had "suffered during his administration not only from a lack of funding, but also drug cartel harassment".

During the hunger strike, he had told media that Michoacan mayors were being forced to give 10 per cent of works budgets to the Knights Templar, a charge also made by residents in other parts of the state.

Ricardo Bautista, president of the mayors' association, said on radio Mr Lopez Mendoza had told others at an association meeting in Mexico City shortly before his death that he was being subjected to extortion by the drug cartel.

Mr Bautista said at least 40 mayors had been killed in Mexico in recent years. In some cases, their own local police forces are believed to have been involved in the killings.

Soldiers moved into another town in Michoacan, Vista Hermosa, on Thursday and detained the entire local police force of 25 officers for questioning.