According to Kumar, the onus of revealing the names of those who allegedly received kickbacks in India in the chopper deal with an Italian firm now lies with Congress as the "scam" took place when the party-led UPA was in power at the Centre.
The Union Minister for Fertilisers and Chemicals also put former Prime Minister Manmohan Singh in the dock in the AgustaWestland chopper deal.
"Along with Sonia, Congress party as well as Manmohan Singh are also answerable as the entire dealing took place when Congress-led UPA government was in power," maintained Kumar, who was here to attend a marriage function.
Gandhi had yesterday rejected as "baseless" allegations linking her and party leaders to bribes in the chopper deal, calling these an attempt at character assassination.