Aam Aadmi Party (AAP) leader Sanjay Singh is the latest party leader to be questioned by federal authorities.

In the state, authorities are investigating alleged fraud related to a now-scrapped liquor sale policy.

After hours of questioning, Mr Singh was arrested on Wednesday evening. He denies the allegations.

In February, Delhi’s deputy chief minister Manish Sisodia was arrested in the same case.

BJP, which runs the federal government, has been accused of playing dirty politics by the AAP.

According to Singh’s lawyer, his arrest was “arbitrary and illegal”. Dhiraj Singh said the charges leveled against Mr Sanjay Singh were laughable because he has nothing to do with money laundering.

AAP leader and Delhi education minister Atishi said authorities had not presented evidence against Mr Sisodia and Mr Singh.

Since last 15 months, the ED and CBI have deployed more than 500 officers in this investigation. “These officers raided thousands of places, but found no evidence of corruption.”

AAP, which emerged from a major movement against corruption more than 10 years ago, is sensitive to questions of financial misconduct.

Additionally, the party has frequently clashed with the BJP as it attempts to position itself as an opposition force.

The ED also filed a case under India’s money laundering act based on the CBI’s investigation. CBI arrested former Deputy CM Manish Sisodia in connection with the case – he also denies the allegations but remains in jail.