The incident was reported to the police by Kumar's son on Sunday, when the family was about to shift some of the artist's best pieces from the studio in the basement of the house.
Police said it was reported that three paintings were found missing during the shifting process, which doesn't establish the date or time of the theft and it has proven to be a big hurdle in the investigation.
According to police, besides, there is also no CCTV installed in the basement where such expensive paintings were stacked.
On Sunday, three paintings worth Rs four crore each was found missing from Kumar's basement studio in his east Delhi residence. The stolen canvases belonged to his signature series 'Sad Town' painted in the year 1956.
The 90-year-old artist was awarded the Padma Bhushan in 2010 and Padma Shri in the year 1972.