The family of quarterback Dwayne Haskins has filed a civil lawsuit claiming he was drugged as part of a "blackmail and robbery conspiracy" the night before his death.

The Pittsburgh Steelers star was trying to cross a south Florida motorway in the early hours of April 9 last year when he was hit by a truck. He was pronounced dead at the scene.

Haskins had been in the area for training with his Steelers team-mates ahead of the 2022 season.

On Monday - a year on since the 24-year-old's death - the family's lawyer Rick Ellsley issued a statement.

"It is believed that Dwayne was targeted and drugged as part of a blackmail and robbery conspiracy," he said.

"In fact, his highly expensive watch was stolen from him shortly before his death."

Mr Ellsley said "many questions remain unanswered" and the lawsuit - filed in Florida on behalf of Haskin's widow Kalabrya and his parents - was "an important step in the process of uncovering the complete truth about this tragedy".

Kalabrya Haskins is listed in the lawsuit as the plaintiff and personal representative of Haskins' estate, and is seeking a jury trial and unspecified damages related to his death.

The lawsuit lists four people, two restaurants, and a hotel among defendants connected to the alleged conspiracy.

Included are the driver and owner of the truck that struck Haskins. The lawsuit claims it was exceeding the speed limit, had worn tyres and brakes, and was overloaded.

It says the pick-up truck Haskins had rented had a mechanical defect that caused it to run out of fuel.

The family also alleges the state highway department didn't properly maintain and light the road, or post a lower speed limit while construction work was being done. They say a temporary sign blocked visibility on the motorway.

Mr Ellsley said the lawsuit will allow him to subpoena documents and question those "who have knowledge about the events leading up to Dwayne's death".

He did not disclose any details about the alleged blackmail and robbery conspiracy.

Broward County Medical Examiner's Office said in a report last May that Haskins died of blunt force trauma.

The manner of death was ruled an accident.

The medical examiner's toxicology report concluded Haskins was drunk at the time. One sample showed Haskins had a blood alcohol level of 0.24 per cent, three times Florida's legal limit of 0.08 per cent.

It also showed that Haskins tested positive for ketamine and norketamine. Both drugs can be used as medical anesthetics or recreationally. It is unclear whether Haskins was prescribed these medications.

Haskins signed for the Steelers in early 2021, having previously been with the Washington Commanders.

He played college football at Ohio State, where he won a number of titles and set several passing and touchdown records.