Hra related documents.

Hello Experts, 

Employees those who have taken house loan, they are residing in rental house and Claiming HRA as well. They said that, from the loan amount they have purchased a house which is not occupied by no one, their parents are residing in that home, they purchased a plot etc..,and they claim interest and repayment of housing loan. I thought that, they are deceiving us by providing fake bills. was there any remedy for this, suggest me .