[NEW DELHI] India's upper house of parliament has rejected Vijay Mallya's resignation of his seat, saying a letter the embattled tycoon sent from Britain did not conform to "procedures" or carry an original signature.
The 60-year-old multimillionaire left India for Britain in March owing more than US$1 billion in unpaid loans, and is under investigation by a parliamentary ethics committee.
India's government has revoked his passport and asked Britain to deport him, but Mr Mallya told the Financial Times last week he had no plans to leave Britain and wanted to reach a "reasonable" settlement with Indian banks.
On Monday he resigned from the Rajya Sabha, or upper house, saying in a letter to the chairman that he did not want his name to be "further dragged in the mud" and calling the accusations against him "false and baseless".
But Rajya Sabha Chairman Hamid Ansari said late Tuesday that the letter was not valid.
"Hamid Ansari, Chairman, Rajya Sabha does not accept the resignation of Vijay Mallya," Mr Ansari's aide, Gurdeep Singh Sappal, posted on Twitter.
"His resignation letter does not conform to prescribed procedures and does not bear signature in original."
A spokesman for Mr Mallya declined to respond to the statement, which Indian media said indicated the parliamentary ethics committee intended to expel him rather than allow him to resign.
The panel has already voted to end his membership and asked him to explain his conduct.
Critics say the government has not done enough to tackle the issue of wealthy individuals such as Mr Mallya, once dubbed the King of Good Times for his lavish lifestyle, failing to repay bank loans.
The debts relate to Mr Mallya's now-defunct Kingfisher Airlines, which shut down in 2012 having never made a profit.
Last month an Indian court issued an arrest warrant for him after he repeatedly failed to appear before investigators looking into Kingfisher's finances.
A two-time independent MP, he also ran a liquor empire and is a part-owner of the Force India Formula 1 team. His Twitter profile now describes him as a "former member of parliament".