Third party liability

Sir, I sold my car on 7th October 2016. It was registered in the Buyer’s name with effect from 15 the November 2016 by the RTO. I had to hand over to the Buyer the insurance policy as it is obligatory for RTO to itransfer ownership to buyers name, along with other documents.Buyer did not transfer insurance policy in his name. Insurance company informed me today that car met with accident on 12th January 2017 and there is third party claim of Rs 7 lakhs. Company asked me why I did not inform them of the accident within 24 hours. I have replied that I did not do so since I learnt about the accident only through their letter. I have sent all papers to them, including Vehicle Sales Agreement on stamp paper where Buyer acknowledges that he is responsible from the instant he takes delivery for all accidents, litigation, maintenance of valid insurance etc. Please advise me why insurance company has written to me, whether I have any liability for the third party claim. I am nearing 80 and extremely anxious Sivaswami