An Australian man has been charged in the deaths of a California married couple in their 80s last week, when he allegedly collided with their car while driving on the wrong side of the road. 

Luke Nardini, 31, has pleaded not guilty to two counts of vehicular manslaughter in the Sept. 1 deaths of Jack and Linda Davis, both 80. 

San Mateo County prosecutors allege Nardini was driving a BMW M4 at around 5 p.m., when he moved onto the wrong side of the roadway after encountering a road closure, FOX San Francisco reported. 

CALIFORNIA AUTHORITIES LOCATE, IDENTIFY BODY OF MISSING NETFLIX ENGINEER FOUND IN SAN FRANCISCO BAY

"Nardini forgot to move back to the right side of the road, as they drive on the left side in Australia," prosecutors said.

Nardini drove the wrong way for about two miles at speeds of 55 to 60 mph before colliding into a Ford Taurus. The Davis' were passengers in the back of the car and died. Two others were injured. 

Australian man kills California couple

Luke Nardini, 31, is accused of driving the wrong way on a roadway and killing a California couple in their 80s.  (San Mateo County Sheriff's Office)

Nardini sustained a fractured vertebra and was taken to a hospital. Drugs and alcohol are not suspected to have played a factor. 

Media reports said Nardini's mother wrote in a now-private Facebook post that her son felt "terrible" about what happened. 

"He has expressed again how sorry he is about what has happened," she wrote. "He wanted to relay to us that he is OK and is being treated well."

CLICK HERE TO GET THE FOX NEWS APP

Nardini is being held at the San Mateo County jail on $20,000 bail. His next court date is Sept. 11. The Sydney Morning Herald reported he was supposed to return to Australia after a three-week trip to the U.S.  

Fox News Digital has reached out to Nardini's attorney, whose office declined to comment on the case.