American swimmer Michael Phelps is "probably not" the greatest Olympic champion of all time, despite winning a record total of 19 medals, London 2012 Games chief Sebastian Coe said on Wednesday.
Phelps eclipsed the previous record of Soviet gymnast Larisa Latynina's 18 medals, when the U.S. won gold in the 4x200 metres freestyle relay at the aquatic centre on Tuesday night.
Coe, a twice 1,500m Olympic champion, said: "I think you can say it is self-evident that he is the most successful. I am not sure he is the greatest.
"It is a pretty good haul, but who is the greatest? In my opinion he is probably not."
Phelps is no longer the phenomenon of four years ago when he won eight gold medals at the Beijing Games and has so far failed to win an individual gold in London.
But he has already added three more medals at these Games to his tally - a huge success by any athlete's standards - and with three events to come in his fourth Olympics before he retires, he can further boost his medal count.
Latynina, 77, whose father died in the Second World War battle for Stalingrad, hailed from the Ukraine and competed for the Soviet Union in three Olympics, starting in Melbourne in 1956.
She is one of only two women to win the all-around gold twice, a tribute to her versatility of which she remains justly proud.
"I could throw out a whole series of names, I could throw out Steve Redgrave, I could throw out domestically Daley Thompson," said Coe.
British rower Redgrave won five gold medals between 1984 and 2000 while Thompson, a close friend of Coe, is a double decathlon gold medallist.
"If I wanted to go back a few generations I think what Jesse Owens did in '36 (Berlin Olympics) was unbelievable, Nadia Comaneci. I don't know. It's the global pub game."
Owens won gold medals in the 100m, 200m, long jump and 4x100m relay at the 1936 Berlin Olympics, much to the chagrin of Nazi Games organisers who were eager to use the Olympics as political propaganda to highlight German superiority.
Comaneci of Romania was the first gymnast to achieve a perfect 10 at the 1976 Montreal Olympics.