Bengaluru/Mumbai, July 23 -- The transfer of the late Ratan Tata's shares in Tata Sons to two charitable foundations he created has been thrown into uncertainty after a complaint over the ownership of some of those shares triggered an investigation by the Maharashtra charity commissioner, potentially delaying the implementation of one of the country's most closely watched wills.

The situation has left the four executors of Tata's will-including his half-sisters Shireen and Deanna Jejeebhoy, lawyer Darius Khambata and long-time confidant Mehli Mistry-unable to transfer the 3,368 Tata Sons shares to the Ratan Tata Endowment Foundation (RTEF) and the Ratan Tata Endowment Trust (RTET), according to an executive familiar with the matter.

"Th...