MEXICO CITY (AFP) - The mayor of a town in south-west Mexico and two others have been arrested over the forced disappearance of an anti-corruption activist, the local prosecutor's office said.

Ms Claudia Uruchurtu Cruz, a 48-year-old British-Mexican dual national, was reported missing on March 26 after a protest against the ruling party politician in Nochixtlan, Oaxaca.

Ms Uruchurtu's disappearance prompted an extensive search campaign and mayor Lizbeth Victoria Huerta was identified as a possible suspect.

Huerta was taken into custody on Friday (May 7), along with two other suspects. They have been identified as "likely responsible for the forced disappearance", the Oaxaca state prosecutor said in a statement.

Huerta, who is a member of leftist Mexican President Andres Manuel Lopez Obrador's party and is up for re-election, has denied the allegation.

Mr Lopez Obrador, popularly known as "Amlo", rode a populist wave to power, promising sweeping change in a country fed up with corruption and crime.

Under Mexican law, candidates can continue to stand for elections while facing criminal charges. Candidates have in the past even won elections from jail.

But if the candidate is convicted, they lose their political rights.

Mexico will hold federal elections on June 2 when almost 20,000 local positions will be up for grabs.

Oaxaca, a southern state with a large indigenous population, has been plagued by violence between rival gangs involved in marijuana cultivation.

Throughout Mexico, more than 80,500 people have disappeared between 2006 - when the government launched a controversial military offensive against drug cartels - and December 2020, according to official figures.

In the same period, around 300,000 people have been killed, with most of the deaths blamed on organised crime groups.