The demand has come a day after former chief minister Ashok Gehlot and several other Congress leaders were booked in ambulance scam.
Singh, who was the MoS in the UPA-II government, condemned the CBI case against Gehlot and others and said that it was a "revengeful move".
"Those leaders raised the issue of corruption against Raje and her son and exposed her and as a result of that a CBI inquiry has been ordered against them.
CBI has taken over the probe in the ambulance scam in which it re-registered FIR of the state police naming Ashok Gehlot, Sachin Pilot, Karthi Chidambaram, Ravi Krishna among others as accused.
External Affairs Minister Sushma Swaraj and Raje have been facing flak for "helping" Modi in procuring travel documents in the UK, a country which he has made his home to avoid legal processes in India.
Dushyant Singh, the son of Raje, has been under attack over media reports that his company received Rs 11.63 crore in investments from former IPL chief Lalit Modi in 2008.