The scam relates to reimbursements being claimed against fake boarding passes and bills from the Rajya Sabha Secretariat. Sahani claimed he is being framed.
This is the first time a Rajya Sabha chairman has given such a clearance, the Rajya Sabha Secretariat sources said.
A CBI official told IANS a charge-sheet in the case was filed last year, and with the clearance from the Rajya Sabha chairman, they will now proceed with "further action" which is likely to be arrest of the MP.
Members of parliament or assemblies cannot be arrested without prior permission of the speaker of the Lok Sabha or the assembly or Rajya Sabha or legislative council chairman.
While this is the first time that the Rajya Sabha chairman has given such a permission, Lok Sabha Speaker Meira Kumar twice sanctioned arrests, first in 2010 against Congress MP Rajaram Pal in the cash-for-query scam, and second time against BJP MP Ashok Argal in the cash-for-vote case.
It was revealed that Sahani and three other accused allegedly used forged e-tickets and fake boarding passes to defraud the Rajya Sabha of Rs.23.71 lakh. Sahani, however, denied the charge.
"Under a parliamentary procedure, permission will have to be given. They are saying I took Rs.23 lakh, if I have even 23 paisa in my account I will resign," he said.
"It is a conspiracy against me because I raise issues related to poor and Dalit."
"I will ask the chairman, I have given all documents and account statements which prove I did not take any money. How is the CBI prosecuting me then?" he added.