Football clubs across England where Gary Speed played have said they are stunned by his death.
The Football Association of Wales has told the BBC it appeared that Speed, the national manager for nearly a year, had killed himself. He was 42.
Speed began his career at Leeds United and was part of the side that won the old First Division title in 1992.
In a career that spanned two decades, he also played for Everton, Newcastle, Bolton and Sheffield United.
Cheshire Police confirmed he was found dead at 07:08 GMT at his home in Huntington, Chester. They said there were no suspicious circumstances.
Leeds United said the club was "stunned and saddened" to hear of his death. The flags at Elland Road are flying at half-mast as a mark of respect.
In a statement on the club's website, Sheffield United - where Speed was made manager following the departure of Kevin Blackwell - said: "Everybody at Sheffield United is extremely shocked and saddened to learn of the death of former player and manager Gary Speed.
"Thoughts are with Gary's family and friends at this distressing time."
'Exceptional role model'
Everton, Bolton Wanderers and Newcastle United have also paid tribute to the Welsh international midfielder.
Everton described Speed as a "popular player" and "boyhood Evertonian", while Bolton said he was "a top-class professional".
Speed joined Everton in 1996 from Leeds United and made 65 appearances, scoring 18 goals.
In a statement, the club said: "Gary was a popular player during his time here at Goodison Park and on behalf of the board of directors, management, players, staff and fans of Everton we would like to extend our sympathies to his family at this extremely difficult time."
Several Everton players also paid tribute to him on Twitter, with captain Phil Neville calling it "horrific news" and Tim Cahill saying Speed was the "the ultimate pro on and off the pitch".
Speed was captain at Bolton Wanderers, where he played from 2004 to 2007.
Chairman Phil Gartside said: "We are all stunned at the news about Gary.
"Not only was he a top-class professional but was a wonderful person who is very fondly remembered by all of us."
The board, manager, staff and players of Newcastle United issued a statement saying: "Gary was an inspirational and much-loved player at Newcastle United during his time with the club from 1998 to 2004, making 285 appearances and scoring 40 goals.
"He was an excellent servant to the club, the ultimate professional and an exceptional role model for younger players."
Newcastle defender Steven Taylor, who came into the first team at St James' Park when Speed was the side's senior professional, expressed his gratitude for the help the midfielder gave him at the club.
"It is a sad, sad day. I played with him when I came through the ranks," Taylor said.
"He helped me through, he was an absolute machine - the best professional in football.
"He had that aura about him. He always had time for the young lads and helped them feel good about themselves."