Gill was the most senior Indian combatant officer captured at the surrender of Singapore in 1942. Immediately after surrender the Japanese separated British from Indian prisoners of war and handed over the latter to Capt Mohan Singh, captured two months earlier and now at the head of an active if unofficial 'Indian National Army' (INA) supported by the Japanese. Mohan Singh saw no reason to defer to his fellow, senior, Sikh, and Gill's attitude was cautious, a caution he maintained in the Indo-Japanese talks of February-March 1942 in Singapore and Tokyo, which confirmed the existence of the INA and of its civilian equivalent the Indian Independence League.
The Singapore talks, hard upon apparently final British defeat, took place during the worst days of the Japanese terror. The Indians were invited to co-operate with the Japanese in the interests of Indian independence. They accepted. It is hard to see what else they could have done.
None the less, they set out their own terms, Indian nationalist terms, and when towards the end of 1942 their terms were rejected, they faced the Japanese, disbanded the INA and reduced League activity to the minimum.
While the INA was being formalised during the summer of 1942, Gill, kept out of the mainstream as 'Adviser', was asked by the Japanese to undertake Intelligence operations in Burma. Seeing in this the possibility of escape, Gill agreed and formed a spy ring that was largely an escape organisation through which three officers and about 15 soldiers, all Sikhs, escaped to India in October/November 1942. One of the escapers was Gill's second-in-command and friend Major Dhillon. Dhillon carried with him INA organisation tables, lists of appointments and full documentation on Indian dealings with the Japanese - the basis of India's successful security operations against Japanese-inspired espionage and fifth column activity throughout the war.
Dhillon's escape was discovered before Gill could escape himself and he was arrested on 3 December 1942 for communicating with India through Dhillon, and remained in Japanese custody until their surrender in 1945.
On his release, Gill was blamed, as senior combatant prisoner of war, for not having prevented the formation of the INA and was forced to leave the Army. Had the Indian authorities understood the full horror of British defeat and Japanese atrocity that gave birth to the INA, which they did not, they would have realised that he could not have done this. He should have been cleared.
It is apparent from Kuldip Singh's obituary that in his later career Gill allowed a different version of his past to emerge. However that may be, he served his country and the Allied cause well in 1942, and was very ill rewarded.