Chand, who runs his own building company, posted a thank you on Facebook last night, and says he was contacted by one of the men who helped his father-in-law.
"I've got some messages from some of those who were there, from one man who says he was the one who called the ambulance but according to him there were two or three people there giving CPR and a lady there communicating with the ambulance people."
He's still searching for the remaining people and is hoping to meet the rescuers in person to thank them for saving his father-in-law.
Chand is a "first aider" himself and says he knows what it takes to be able to reach out and help those in need.
He says his father-in-law is still in ICU and last night he was still unresponsive.
A police spokesperson confirmed they were called to a medical event at 11.20am on Waioni St, close to the overbridge.
Police assisted with traffic control as the ambulance worked on the patient.