They said they do not believe the crash was deliberate.
Court records show Samarasinghe previously had his licence suspended in February. He appealed the suspension in April but was unsuccessful, the Sydney Morning Herald reported.
New South Wales emergency services responded to a car crashing into Newcastle Knights fans as they waited to farewell the team bus as it departed for the NRL grand final.
Thousands of fans were at the event when the crash happened.
Ten people were injured, including a 5-year-old girl and a 67-year-old man, who were initially reported to be in critical condition.
Both are now in a serious but stable condition, the ABC said.
Six people remain in John Hunter Hospital, while four others have been discharged.
One of the injured fans, Chris Clancy, suffered a broken collarbone.
He described the festive atmosphere moments before the crash.
“We’re there at the roundabout having fun – cars going past, beeping their horns, people waving,” he told AAP.
“The next thing, this car stops [at] the roundabout and then he just floored it on the wet ground, lost it.
“It happened in seconds, but when you stand there, seeing the car coming at you, I honestly thought I was going to die. It just felt like slow motion.”
Video of the incident appeared to show a BMW after it collided with the crowd, with a helicopter later flying in and emergency service vehicles surrounding the scene.
Australian Prime Minister Anthony Albanese said he had offered support to the state government.
“My thoughts are with everyone injured or involved in the horrible incident this morning in Newcastle,” Albanese wrote in a social media post.
“I want to acknowledge and thank emergency services and police for responding so quickly, and their ongoing work in treating the injured.
“Rugby league brings people together, and this should have been a weekend of excitement and pride for Newcastle fans.
“I have spoken to the NSW Premier Chris Minns and offered our support.”
Premier Chris Minns said his thoughts are with the families impacted by the incident.
“It’s heartbreaking to see fans who were sending off their grand final team involved in such a terrible incident,” he wrote in a social media post.
“My thoughts are with the families and friends of loved ones who have been involved or injured in the crash. I also want to thank emergency services including police and ambulance who are responding to this tragedy.
Emergency helicopters were seen responding to the incident.
“We’ve seen how this grand final has brought Newcastle and Hunter communities together and I hope the whole community remains united as we continue to respond.
“As large numbers of fans and families make their way down to Sydney for the grand final, please drive safely and take caution on roads.”
Fire engines, police and ambulances were seen at the incident.
Meanwhile, Australian Rugby League Commission executive chairman Peter V’landys said he and the commission were “deeply saddened” by the incident.
“Our thoughts are very much with those injured and anyone impacted by these events, not to mention the entire Knights community who have come together in jubilation to support their team.”
Knights captain Kalyn Ponga said on Instagram that the team’s hearts were with everyone affected.
“We’re thinking of you, your families and everyone in our Newcastle community,” Ponga wrote.
“Sending our love and support.”