Moving footage of Sol3 Mio's Pene Pati breaking down on stage has been viewed by nearly 10,000 people across the globe.
The opera singer's uncle-in-law was one of the people shot in Christchurch's horrific mosque massacres.
"My wife cries from the other side of the world today as her uncle is one of the injured, still waiting on hospital [to hear] whether he has survived or not, in the incident today in Christchurch," Pati wrote on Facebook on Friday.
Pati is married to successful soprano Amina Edris who is an Egyptian-born New Zealander.
It is not clear what the uncle-in-law's condition is.