Indologist Koenraad Elst mentions that first there was Jaya (original Mahabharat) written by Vyasa, then it expanded into Mahabharat. Here's the video where he says so https://youtu.be/myBXPSYIiTY?t=1239
He also says Mahabharat also mentions this. Could anyone cite the verses which say certify this evolution of Mahabharat?
Please prefer to mention BORI verses if possible as its easy to find and I have copy of it.