"Sudheendra Kulkarni has been sent to jail today. The bribe givers are in the Government and those who exposed are in jail. What justice under this raj," Swaraj commented on the microblogging site twitter.
Sources said that the BJP has decided to make a major issue out of it and Swaraj and Arun Jaitely will address a press conference on the issue tomorrow.
Rising to Kulkarni`s defence, the BJP said that whistleblowers cannot be charged and wondered why those who had benefitted from the scandal had not even been questioned.
"There cannot be a charge of entrapment against whistleblowers when there is a charge of bribe-giving against others," Leader of Opposition in Rajya Sabha Arun Jaitley told reporters, in a reference to former SP leader Amar Singh who is an accused in the case.
Singh has been charged with providing the money to be paid to the three BJP MPs in the cash-for-vote scam.
Jaitley said such an exercise is undertaken often by the CBI and the police to expose bribe-takers.
Kulkarni was sent to judicial custody till October 1 for his alleged involvement in the July 2008 Cash-for-Vote scam.
Referring to Congress and SP, BJP spokesperson Nirmala Sitharaman wondered why those who had benefitted from the scam had not even been questioned while the whistleblowers have been sent to jail.