A McDonald’s employee saved the life of an off-duty police officer by jumping through the restaurant's drive-thru window when she suddenly lost consciousness.

Pedro Viloria was about to hand the woman her order at the branch in Doral, Florida, when he noticed she had irregular breathing.

The off-duty policewoman, who had her two children in the back of the car, suddenly lost consciousness causing her foot to slip off the brakes and her car to roll forward.

CCTV footage reveals the moment Mr Viloria sprang into action as he jumps onto the counter and propels himself out of the window.

According to CBS Miami, Mr Viloria asked the children to call the police and went to seek out help from inside the restaurant.

"In that moment, I thought, 'I'd rather save that woman's life,'" Mr Viloria told WPLG. "I see she's, like, inflating her neck, like trying to breathe, like 'ahh,' and basically I thought something was going wrong."

He was reportedly able to summon two firefighters eating breakfast and an off-duty paramedic, who assisted the woman before she was taken to hospital, where she was said to be in a critical condition on Tuesday.

Miami-Dade Police Department revealed no further information about her condition.

A McDonald's spokesperson said: "First and foremost, our thoughts and prayers are with the officer and her family during this difficult time. I think I speak for our McDonald’s family when I say how proud we are of Pedro.