Hemant's death comes three years after the 82-year-old singer lost her daughter, Varsha, in 2012. Varsha was suffering from depression and committed suicide.
Hemant's cousin, Radha Mangeshkar, said they had hoped for his recovery but the musician passed away on September 26.
"He was suffering from cancer for past three years... the family was in trauma since then. We did hope that he would get well. He passed away in Scotland on September 26. He was 66," Radha, Bhosle's niece.
The family was set to celebrate Lata Mangeshkar's 86th birthday on September 27 but they cancelled it after they got to know about the demise of Asha's eldest son, she said.