Paulo Radmilovic's Olympic medals haul was only surpassed by Steve Redgrave
A search is on for the four gold medals won at the Olympics by a man dubbed "Wales's greatest ever sportsman".
Cardiff-born swimmer and water polo player Paulo Radmilovic won two golds at the 1908 London Games, another in 1912 and one more at Antwerp in 1920.
He was not eclipsed until rower Sir Steve Redgrave won his fifth gold medal in successive games in Sydney in 2000.
The Welsh Sports Hall of Fame wants to include them in an exhibition of sporting greats in Cardiff.
Trustee Rob Cole said: "They should be on display close to his home to act as an inspiration to future generations."
Radmilovic was the first Welshman to win an Olympic gold, nearly 100 years ago, when he was 18.
The third son of a Dubrovnik-born publican, who ran the Glastonbury Arms in Bute Street, Cardiff, he became one of the original 10 inducted in to the Welsh Sports Hall of Fame 20 years ago.
Next week a plaque is to be unveiled at Cardiff International Pool to honour him, paid for by the London Olympic Committee and the assembly government.
Radmilovic won his first gold as part of the British water polo team. Two days later he was in the team which one the 4x200m swimming relay.
He two other medals were also for water polo and he competed in the sport in the 1924 and 1928 Olympics.
Mr Cole said he has spoken to Radmilovic's surviving family in Wales and the Amateur Swimming Association but is still unable to trace the medals.
He said: "He went to five Olympic games, won four gold medals, broke world swimming records and was just an incredibly talented and competitive man.
"These medals are part of the rich sporting heritage of Wales and it would be great if we could get them back on display in Wales.
"They would be a huge inspiration for the new generation, who we're hoping to inspire London in 2012.
"We need some lasting memory of arguably Wales' greatest ever sportsman."