Prasad said if an investigation is carried out, there will be criminal cases against Vadra.
"He (Vadra) made huge profit of Rs.300 crore in a few years from an intitial investment of Rs.1 lakh," he alleged.
Congress spokespersons Abhishek Manu Singhvi and Randeep Surjewala and general secretary Ajay Maken refuted the BJP's allegations, but it was Priyanka Gandhi, who in Rae Bareli came out all guns blazing against the BJP and said she will not stay quiet.
She accused the BJP of unnecessarily defaming her husband and said the opposition represented "destructive, negative" politics.
"They are behaving like bewildered rats. I knew they would resort to spreading lies a few days before polls," she told media persons in the constituency where her mother Sonia Gandhi is contesting.
