The Philippines' first female Olympic medallist says she fears for her safety after President Rodrigo Duterte's government named her in a chart claiming to show a plot to undermine his rule.

People called out publicly by the president in the past for perceived wrongdoings -- frequently in the form of alleged links to the drug trade -- have ended up dead or in jail.

The claim targeting weightlifting star Hidilyn Diaz surfaced in the closing days of the campaigning in midterm elections, which have been marked by flying accusations.

"I am shocked. I am concerned for my security as well as that of my parents," said Diaz, who became her country's most successful female athlete when she won a silver medal at the 2016 Rio de Janeiro Olympics.

"My mother is terrified because (journalists) are interviewing her and she has no idea why," Diaz tearfully told Philippine television network GMA late Thursday, adding online trolls are now also going after her.

Diaz, 28, was among dozens named in charts released by a Duterte spokesman on Wednesday which allegedly showed links between people he accused of plotting to "discredit this administration".

The charts, which did not substantiate the accusations, included the names of opposition politicians, an exiled communist guerrilla leader, journalists and others.

They were released in the closing days of a legislative election campaign thick with flying accusations, including allegations Duterte's family is tied to the drug trade.

The president has found international notoriety for his crackdown on narcotics in which police have killed thousands of alleged dealers and users.

Those accused in the government charts have issued forceful denials, including journalist Maria Ressa, who runs a website critical of Duterte and was arrested twice this year in what press advocates call intimidation efforts.

Diaz posted a video on Facebook Thursday of herself tearfully rejecting any involvement in opposing the government.

"Please do not link somebody who is busy making sacrifices for everyone, for the Philippines. I am merely doing my best to represent the Philippines in weightlifting," she wrote, as she prepares for the 2020 Tokyo Olympics.

Last week Duterte's spokesman Salvador Panelo put out another chart of opposition leaders and Filipino journalists he said were plotting to unseat him.

Panelo avoided issuing an apology to Diaz on Friday, but he minimised her inclusion on the chart and blamed the media.

"There has been a wrong analysis of the diagram by some media outlets," he said in a statement, adding that led to wrong "conclusions" by Diaz.