Helen Mirren has paid tribute to her late stepson Rio Hackford.

Hackford was the son of Mirren's 1997 husband, film director Taylor. He died on Thursday, 14 April, of an unexplained illness.

Mirren captioned an Instagram snap of the actor, "El Rio."

Hackford is most recognized for creating the motion capture for Taika Waititi's droid IG-1 in four episodes of The Mandalorian.

His other notable performances include Toby, an old buddy of Steve Zahn's character David McAlary, on David Simon's HBO drama Treme.

He was also the proprietor of the New Orleans nightclub One-Eyed Jacks, featured in the series.

Hackford's filmography includes Trumbo, Jonah Hex, and American Crime Story: The People v OJ Simpson.

He also appeared in a brief part alongside his stepmother in his father's 2013 romantic comedy Love Punch.

The actor appeared in Pam & Tommy alongside Lily James and Sebastian Stan.

Hackford's wife, Libby Grace, and their two children survive him.