The father of Leeds Carnegie duo Chris and Jack is believed to have died of a suspected heart attack this week.
He was 44 and was a well-respected figure in both codes of rugby, having played for Barrow, Batley and Hunslet as well as representing Yorkshire.
Walker joined Keighley from Otley in the early nineties and played 64 games at Cougar Park, scoring 34 tries and 43 goals, amassing 222 points.
Cougars chairman Gary Fawcett said: “Many of the fans and staff remember Johnny well from the time he played at the Cougars. “From all associated with the club, our condolences go out to his family and friends at this very sad news.”
Tributes to Walker, who also played union for North Ribblesdale, were left on Otley’s website messageboard, with Chris having spent time on loan at the Cross Green outfit.
The Walker family hail from Settle and brothers Chris and Jack have carved out fine reputations in rugby union after rising to prominence at Leeds.
England under-20 captain Chris, 20, signed a new two-year contract with the Championship club last April whilst his younger brother Jack, the England
under-16 hooker, agreed a long term four-year deal.
Speaking on behalf of the club, Leeds head coach Diccon Edwards said today: “We are devastated for the Walker family for their loss.
“Johnny was ever present at our games for as long as I have been involved in the club and was always seen in the stands supporting his boys, whom he was extremely proud of.
“On behalf of everyone at Leeds Carnegie we send our deepest condolences to the Walker family.”