Cheating case

I happened to see a scanned copy of my husband's passport in which spouse's name was shown as jisha. Before that also a railway ticket was found with her name of which my husband developed a story which I had to believe. When I asked about the passport he denied the mattersaying it as a IT techniques and deleted the copy. As he always keep his phone away from me I had to go to nearby passport office and filed a missing passport application introducing myself as jisha. I have received the same copy. I went to that lady's house in Kerala where i found his photo which was taken 10 yrs back and her mother said he is her son-in-law. Again my husband says that everything is fake and passport was created to save her life as she was disappointed of not getting a chance to go abroad. He denies the marriage still. The lady is still working with a government hospital at Delhi and thinking of my children i m not able to take immediate action. What should I do next to find out the lady as I want to meet her personally before proceeding further. According to her mother this marriage has happened 6-7 yrs back. I know jisha's face and have her She is not picking calls but she reads my whatsapp messages. Advice me for the next step.