Mr Soren was arrested by the Enforcement Directorate on January 31.
The BJP's Jharkhand unit on Tuesday released a video clip claiming that arrested former chief minister Hemant Soren does own a piece of land, which the Enforcement Directorate accused him of illegally acquiring.
The claim was made a day after Mr Soren challenged the BJP in the Jharkhand Assembly to prove corruption charges against him, asserting that if the accusations were proved, he would quit politics.
Mr Soren was arrested by the ED on January 31 after a marathon seven-hour interrogation in connection with a money laundering case linked to an alleged land fraud. The 48-year-old Jharkhand Mukti Morcha executive president resigned as the chief minister before the arrest.
In the 58-second video clip released by the opposition BJP, a man, identifying himself as Santosh Munda, is seen saying that the piece of land at Bargain in Ranchi district belongs to Hemant Soren.
PTI could not independently verify the identity of the man shown in the video.
Talking to reporters, Jharkhand BJP president Babulal Marandi said, "The man is the caretaker of the land. It is known to everyone in the area who its owner is."
Mr Marandi, a former chief minister, alleged: "In a bid to hide black money, Mr Soren purchased that land in the name of someone else."
When contacted for their comment, JMM spokespersons did not respond to repeated calls.
"I challenge the BJP to prove corruption charges against me. If someone proves that I possess 8.5 acres of land, I will resign from politics," Hemant Soren had said in his speech during the trust vote of the Champai Soren government on Monday.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)