Questioning Indias failure to secure extradition of Vijay Mallya from the UK, CPI-M General Secretary Sitaram Yechury on Tuesday accused the Modi government of being "lenient" towards the liquor baron.
"The question is if you want to bring Mallya back, you need to have the extradition treaty in order. It has been almost a year and the government is just talking and talking… but nothing has happened," said Yechury.
"I don't know why this government is unable to secure his extradition from a country which is very friendly with India. This government is not taking steps. Otherwise he would have been in India by now.
"This government needs to explain why they are so lenient towards him."
The Communist Party of India-Marxist leader's comments came after the Supreme Court on Tuesday held Mallya guilty of contempt of court and directed him to appear before it on July 10.
Mallya fled to Britain in March 2016 after being pursued for the recovery of Rs.8,191 crore his now defunct Kingfisher Airlines owes to Indian banks.
The Indian government had in February handed over to British authorities a formal request for Mallya's extradition, saying it had a legitimate case against him on charges of financial irregularities and loan default.
India and the UK have an extradition treaty, signed in 1992, but so far only one extradition has taken place under the pact.
Samirbhai Vinubhai Patel was sent back to India in October to face trial in connection with his involvement in the Gujarat riots of 2002.