Dozens of runners who competed in a grueling half marathon from California to Mexico returned to the United States to find that their cars had gone missing. 

The bizarre incident unfolded on Sunday during the San Diego-Tijuana Binational Half Marathon, a 13.1-mile race starting in San Ysidro, California and finishing across the border of Tijuana. 

Runners were shocked to discover their vehicles had been towed while they were racing - with many insisting they parked exactly where race officials and the event's website instructed them to.

Runner Bernice Diaz told FOX 5 San Diego that she and her sister parked at Las Americas Premium Outlets, a location the event's official website explicitly stated would be safe from towing on race day.

'So we get there, and there's no car. I was like, 'Where is my car?' Diaz said. 'I was not the only one. All these people are part of it, which is unfortunate.'

Another runner, Alex Rodriguez, claimed on-site race personnel actively directed him to park at San Ysidro Village near a Popeyes restaurant.

'It's not our fault when the official people of Binational Half Marathon instructed us to park there,' Rodriguez argued.

However, the Binational Race Team is strongly disputing the runners' version of events, denying that any of their staff were assigned to direct vehicles or manage parking.

In a formal statement, organizers said 'all reported towing incidents occurred at the San Ysidro Village parking lot, near Ross and Popeyes,' a property 'not designated or communicated by Binational Race as an authorized parking location.'

The conflicting accounts have left frustrated runners demanding answers and financial reimbursement for their hefty towing fees.

Connie Mendoza, who traveled from Los Angeles for the race and had her car towed, told reporters she has tried contacting organizers via email, phone, and Instagram but has been met with total silence.

'Who's going to give our money back?' Mendoza asked.

Race organizers have not publicly committed to reimbursing any of the affected participants. The Daily Mail have reached out to The Binational Race for comment.