Lions lock Hyron Andrews has died at the team hotel on Friday, the day before the South African club are due to play French side La Rochelle in the European Champions Cup, a fixture that will go ahead in his honour, the team said.
French media reported that Andrews, 31, was found unconscious in a shower cubicle at a hotel on the Ile de Re in France, where the team had been staying since Tuesday.
Emergency services were called shortly after 10 am (0800 GMT) and attended to the player, who was in cardiorespiratory arrest. Their attempts to resuscitate the South African were unsuccessful, the reports added.
"His loss will be felt profoundly by his teammates, coaches, supporters and all who had the privilege of knowing him," the Lions said in a statement.
"Our deepest and most heartfelt condolences go to Hyron’s wife, Maiglin, their young sons, and the entire Andrews family.
"We hold them in our thoughts during this time of unimaginable grief and ask that their privacy be respected as they mourn."
The Lions gave no details about the circumstances of Andrews' death but confirmed Saturday's game will go ahead.
"In honour of Hyron, the Lions will fulfil their opening match of the Champions Cup against La Rochelle," the team statement added.
Andrews had a spell with the Sale Sharks in England and played for the South African under-20 side, but was not a capped senior international.
European Professional Club Rugby Chairman Dominic McKay said in a statement: "The thoughts of everyone at EPCR and the wider international rugby community are with Hyron’s wife Maiglin, his young sons, wider family, friends, teammates, the Lions and all those who knew and loved him at this incredibly difficult time."
Andrews' death comes 10 years to the day after Munster coach Anthony Foley died aged 42 in his Paris hotel ahead of a Champions Cup match against compatriot Ronan O’Gara’s Racing 92.
O’Gara is now La Rochelle coach and Irish media reported that he visited the Lions at their hotel to offer condolences.
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