Former Cologne and West Germany forward Dieter Muller has suffered a heart attack, third division Kickers Offenbach, the club where he was president for 12 years, said on Friday.
The club did not give any further details but German media said he was in a coma.
The 58-year-old played 326 matches during eight seasons with Cologne, scoring 231 goals. He was the Bundesliga's leading scorer in 1976/77 with 34 goals and the following season with 24 when they won the title.
In 1977, he scored a Bundesliga record six goals in the 7-2 win over Werder Bremen, a feat which is not recorded on tape as television staff had gone on strike that day.
Muller made only 12 appearances for West Germany but scored nine goals, including a hat-trick in a memorable European championship semi-final against Yugoslavia when they came from 2-0 behind to win 4-2 after extra time.
He also played at the 1978 World Cup in Argentina.
Muller started and ended his playing career with Kickers Offenbach and also had stints at Saarbruecken, French side Girondins Bordeaux and Switzerland's Grasshoppers.
Borussia Dortmund's Mario Gotze ruled out of Champions League final against Bayern Munich
Malaga coach Manuel Pellegrini will leave the La Liga club at the end of the current season
Stoke City and manager Tony Pulis part company by mutual agreement after seven years
Andy Carroll pulls out of England's friendly internationals against Ireland and Brazil
Ten years on, the legends speak to FFT
Your questions answered by an A to Z of legends
He's here, he's there, he's...
The cost of Premier League away travel
Nike CR7 IX for you
FourFourTwo is brought to you by Haymarket Consumer Media & FourFourTwo is part of Haymarket Sport
| International Licensing | © Haymarket Media Group 2010