The twins, who died on Tuesday, had a common thorax, spine, heart, abdomen, stomach and pelvis and were earlier under the observation of doctors in the Sion Hospital.
Diagnosed in an ultrasonography test conducted at the hospital during their mother's 32nd week of pregnancy, the twins were born at the civic-run Sion Hospital here in July this year.
Their parents, Shahin Khan and Irshad Khan, an assistant in a Dadar shop, and doctors had a tough time in treating the twins because of their complicated body structure.
"We are going to conduct the postmortem to ascertain the exact cause of death," the doctor from Sion hospital said.