FOR 12 years, a man reportedly locked his girlfriend's pants shut with a "chastity belt" each morning in fear that she would be unfaithful.

The woman, 25, from Zacatlame, a poverty-stricken community in Veracruz, Mexico, finally told police about her plight when she desperately needed to use the toilet but was too afraid to cut her pants open, CNN en Español reported.

The woman, who had been living with her older boyfriend, José Antonio, 40, since the age of 13, told police that she was in fear of him.

Police then arrested Antonio and he admitted to putting a padlock on the woman's pants and gave officers the key to release it.

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"To the surprise of the authorities, the woman refused to press charges once the man was detained," said Araceli Gonzalez, executive director of the Equifonia, a women's rights group.

"The suspect was still taken into custody on a misdemeanour charge, but released a few hours later," she said. "The following day, the suspect signed a statement promising never again to use a padlock on his girlfriend or abuse her in any other way."

State authorities said there wasn't much they could do because the woman refused to press charges.