Media playback is unsupported on your device Media caption The cause of the crash is unclear

The operator of a limousine company involved in a deadly crash in upstate New York on Saturday has been arrested on a charge of negligent homicide.

They say the driver did not have a proper licence and the vehicle should not have been on the road.

Nauman Hussain, operator of Prestige Limousine, denies the charges.

All 18 people in the limousine and two pedestrians died when the driver lost control in the town of Schoharie, west of the state capital Albany.

The company's lawyer, Lee Kindlon said Mr Hussain's girlfriend and brother had been brought to a police station for "initial questioning."

This was America's deadliest transport accident since 2009. Those killed included four sisters and two pairs of newlyweds.

The car had been taking the group to a birthday party and failed to stop at an intersection in Schoharie, police said.

Eyewitnesses said the SUV-style limousine had shot across the junction and hit another car before ploughing into people in a shop car park.

The passengers would not have been required to wear seatbelts, police said.

They added that the vehicle had failed inspections last month. Mr Hussain's lawyer denies this.