In a letter written to Narendra Modi from the Open Platform for Netaji, the family members said that an SIT should be constituted under the guidance of a sitting judge of the Supreme Court to investigate into the matter.
"The SIT would include professionals from all relevant fields of expertise eg Central Home Department, Intelligence Bureau, Central Bureau of Intelligence, External Affairs Ministry, historians and researchers. The SIT would scrutinies all the declassified documents and interview/cross examine witnesses and concerned persons," the letter said.
Netaji's grandnephew Chandra Kumar Bose said that they have also sought an appointment with Modi next month to press for their demands.
"There have been many inquiry commissions to investigate into his disappearance but they were either inconclusive or not accepted by the governments. If an SIT is formed under a sitting judge it will have full authority and wide acceptance as it would be based on facts and evidence," he said.
When under house arrest by the Britishers, Netaji had escaped from India in 1941 to seek international support for India's freedom struggle.
After organising the Indian National Army with Japanese help he went missing in 1945, giving birth to India's most debated and puzzling mystery as since then no whereabouts of his life has been confirmed.
Justice Manoj Mukherjee Commission of Enquiry, which was set up in 1999, had rejected the opinion that he died in a plane crash in Taiwan on August 18, 1945.
They have also demanded that a central research centre should be established in Netaji's name, either under a relevant union ministry or the National Archives to "rectify distortions" in the history of India's freedom struggle.
They also want that the National Defense Academy should be renamed after Netaji as 'Netaji National Defense Academy of India' while 23rd January, Netaji's birthday should be declared as 'Deshprem Diwas', or 'Patriot's Day'.
The Central government till date had instituted at least three judicial commissions to probe the matter and each time their reports were subsequently rejected by the government.
Earlier also the Shah Nawaz Commission report and Khosla Commission report were rejected by the government.