Former Wales prop Brian Williams died suddenly on Wednesday of a suspected heart attack. He was 46.
Williams won five Test caps for Wales over two seasons after making his international debut against Scotland at the Cardiff Arms Park in 1990.
The Pembrokeshire farmer made over 250 appearances for Neath between 1983 and 1995, helping the Welsh All Blacks to two WRU Challenge Cups, the inaugural Heineken League title and two Western Mail championships.
Welsh Rugby Union chairman David Pickering, who played with Williams at Neath, said: “I cannot recall ever having seen a fitter player in rugby. He was uncompromising, never knew the meaning of defeat and was a fantastic forward.
“We fashioned the style of play at Neath around Brian and our mobile forwards. He was the leading light at the club and a man that everyone revered and followed.”
Williams featured in the Neath side that set new world records for tries (385) and points (1,917) in the 1988-89 season.
Bristol lock Gareth Llewellyn, Wales’ most capped forward, played with Williams for both club and country.
Llewellyn said: “Brian was amazing – he was the fittest and most powerful man I ever played rugby with.
“Pound for pound he was the strongest man in the game. He brought mental toughness and hardness to Neath and gave us all the lead in those areas.
“The Neath team of the late 1980s and early 1990s was one of the best sides I have ever played in and it was down to players like Brian that we were so successful and revered.”