Boxing-Scottish great Ken Buchanan dies aged 77

(Reuters) - Scotland's first undisputed boxing world champion Ken Buchanan has died at the age of 77, the former lightweight's charity foundation said on Saturday.

Edinburgh-born Buchanan beat Panama's Ismael Laguna in Puerto Rico for the WBA title in 1970 and took the vacant WBC belt a year later after fighting Ruben Navarro in Los Angeles.

He lost the WBA title to Panama's Roberto "Hands of Stone" Duran in a controversial 1972 fight at New York's Madison Square Garden, with the Scot taking an apparent low blow to the groin on the bell at the end of the 13th round.

Buchanan was unable to come out for the 14th and the referee awarded the fight to Duran, who had been comfortably ahead on points. There was no rematch.

The Scot, who was also named as the 1970 Fighter of the Year by the Boxing Writers Association of America ahead of heavyweights Muhammad Ali and Joe Frazier, was diagnosed with dementia last year.

"It's with great sadness that we have to inform you that Ken Buchanan passed away peacefully in his sleep this morning," the Ken Buchanan Foundation said in a statement.

(Reporting by Alan Baldwin in London; Editing by Hugh Lawson)