The Congress on Tuesday questioned Prime Minister Narendra Modi's "continued silence" on the Lalit Modi issue, saying there cannot be different set of rules for UPA and BJP ministers.
The opposition party also said that the claim about travel documents being issued to the former Indian Premier League chief on humanitarian grounds was "false" and demanded a Supreme Court-monitored probe into the entire controversy.
"We have to ask the prime minister directly (as to) why is he quiet. Can there be two parameters? Can there be a different set of rules when you talk of probity and correctness for ministers of the UPA and the BJP? Why is the prime minister silent," asked Congress spokesperson Anand Sharma while speaking to reporters.
"The PM has to speak about this nexus... there are many questions which have been thrown up. We demand a through investigation into this affair," the Congress leader said.
"They should respect the (probity) parameters they had set for the UPA ministers," he said.
Branding Lalit Modi as a "fugitive" and a "wanted" person, the Congress leader said: "An unacceptable concession was made to this person who should instead have been extradited and prosecuted under the law of the land."
"Why is the (NDA) government protecting him? Whoever is involved should not remain in the government," he added.
Anand Sharma also demanded a Supreme Court-monitored probe into the matter.
"This is not restricted to the travel documents or the humanitarian facade. It has to be done by the Supreme Court and also a special investigative team has to be set up. This has to be taken to a logical conclusion," he said.
Sharma said the Lalit Modi controversy needed to be probed. "He knows some people and they are protecting him," he said.
It was not correct for the Narendra Modi government to facilitate travel documents for somebody who is wanted by law in India, the former union minister said.
"When there was no specific query from the authorities in the United Kingdom to the external affairs minister Sushma Swaraj on the matter, why did she commit impropriety," Sharma questioned.
The Congress leader said that no invasive surgery was conducted on Lalit Modi's wife. "It can be verified from the particular medical facility. After reaching that place... from August 8 onwards, Lalit Modi, his wife and another family member were holidaying."
"Once you gave him a passport in London, he should have been put on a plane and brought to India," Sharma said.
He said it was not only the external affairs minister, but also others who were responsible for shielding the former IPL chief.
"Sushma Swaraj did what was unwarranted; others also can be accused of dereliction of duty and protecting Lalit Modi. Rajnath Singh is the home minister; he has all the intelligence inputs on all offenders; he is instead endorsing the external affairs minister," he added.