Ishmeet, 19, died mysteriously in a swimming pool at a beach resort in Maldives July 29. He was there for an event.
Kamal Singh revealed that ADK hospital in Maldives where Ishmeet was taken from the resort said in its report that "drowning seems to be a secondary cause of death" in Ishmeet's case.
"If drowning was supposedly a secondary cause, then we would like to know the primary cause of his death, " Kamal Singh told.
The late singer's family has been urging the central and the Punjab governments to order a Central Bureau of Investigation (CBI) probe into his death. They are now heading to the Maldives on their own Wednesday to find the facts.
His family says the post-mortem and forensic laboratory reports state the reason of his death was drowning, but his body had severe injury marks on the forehead and temple.
"We want a proper enquiry from CBI. We are not against anyone nor are we pinpointing someone. Our visit to Maldives is in the knowledge of the Punjab chief minister, the prime minister and the Maldives government. We just want to know the reason for the injuries on Ishmeet's head, " said Gurpinder Singh.
"If the investigation results are able to convince us about the injury, we will quit the matter then and there but till then we are not sitting quietly, " added a bleary-eyed Gurpinder Singh.
Explaining the severity of injuries suffered by Ishmeet, Kamal Singh said: "The injuries on his head are being downplayed. Ishmeet suffered a hematoma that is a blood-filled cavity on the temple and a linear cut on the forehead. We are ready to believe that he died due to drowning as per the lab reports, but we just want to know the reason behind the injuries."
Kamal Singh also informed that Ishmeet suffered a blood flow out of his nose and mouth during drowning, which is not normal in drowning cases.
"When I contacted the pathologist, who conducted the post mortem in Ludhiana to find out about the same, we were told that the air sacs in his lungs burst so there was a blood flow out of the two possible outlets - nose and mouth.
"According to medical science, when a person drowns, his alveoi (air sacs or cavities) in the lungs get filled with water and expand and burst but do not allow any outlet for blood from either the nose or the mouth as the person dies of suffocation, " he explained.