The mother of a controversial transgender track star has blasted the rule that allows biological female rivals to stand on the podium despite losing.

AB Hernandez, who was born male, shared the top step with female rivals at a California track meet on Saturday, despite comfortably beating them in the division championships.

The athlete had easily beaten biological female competitors in the long jump, high jump and triple jump at the CIF Southern Section finals in Moorpark.

When it came time for the podium celebrations, the announcers told the crowd that each event had two 'co-champions', including Hernandez - a rule that was brought in last year to seemingly appease the defeated young girls.

According to Fox News, Jurupa Valley High School athlete Hernandez first won the long jump by more than a foot over Moorpark High's Gianna Gonzalez, but the latter stood alone on the top step of the podium while Hernandez was absent.

In the second event, Hernandez won first place in the high jump by two inches, beating Gwnneth Mureika of Oak Park. At the podium celebration, both stood together on the top step.

The final event was the triple jump, in which Hernandez reportedly won by nearly two feet over Malia Strange of Shadow Hills. Strange was mysteriously absent from the podium celebration, leaving Hernandez to stand alone without the 'joint champion'.

It has since emerged that Hernandez's mom, Nereyda, shared a post after the event had finished, condemning the new rule.

Originally posted by charity Rainbow Families Action, it shows a picture of a letter from the California Interscholastic Federation (CIF) giving the green light to the rule change.

'All these big, tough ex-athletes at CIF, and the most courage they could muster was to hand this to coaches at AB's meet today,' the campaign group commented in their original post.

'Not one of them was brave enough to look her or her mother in the eye and say: "This whole project of violating Ed Code is aimed at you. A child."'

In a separate post about the event itself, Nereyda added: 'Today at the CIF Track & Field Finals, my heart was full watching AB compete.

'No matter how differently she may be seen by some, she continues to walk onto that field with the most beautiful smile on her face, gives EVERY event her ALL, and carries herself with grace, determination, and sportsmanship.'

Hernandez now moves on to next Saturday's CIF preliminaries, with a chance to get back to the state finals for a second straight year.

Last year, the CIF authorities brought in a 'pilot program' - amid much fury - that awarded any female athlete who finished behind a trans rival the chance to share the top step of the podium as a joint winner.

It has been reported that the same circumstances will be in place for the remainder of the postseason.

Last week, one of Hernandez's biggest rivals had threatened to protest against the trans athlete if she were on the podium too.

Reese Hogan, of Crean Lutheran High School, went viral 12 months ago with a similar protest, in which she finished behind Hernandez but then made a point of taking her place on the top step of the podium. 

When asked if she would take a stand again this year, Hogan told Fox News Digital: 'If the opportunity presents itself, we'll see, yeah.'

On Saturday, Hogan finished third in the high jump, sixth in the triple jump, and did not make the finals of the long jump. 

'This is my third year competing against a transgender athlete, and last year I was stripped of a CIF Title. I basically worked my whole career to get to that point,' Hogan told the outlet during the emotional interview earlier in the week.

'It's just really disappointing to go into a competition knowing you already lost.

'I'm here to stand up for girls in girls' sports and to call out CIF and the state of California for their poor leadership and lack of support for female athletes.'