The Central Bureau of Investigation (CBI) Thursday said it had been asked to probe the suicide by Sadhick Batcha, a close aide of disgraced former communication minister A. Raja.
A CBI official confirmed to IANS that the Tamil Nadu government had transferred the suicide case to it.
The Tamil Nadu government earlier on Thursday said it was transferring the case as the CBI was investigating the spectrum scam and had questioned Batcha.
Batcha, 47, was found hanging at his Chennai home on Wednesday afternoon. His autopsy was conducted on Thursday and the body handed over to the family.
Batcha was under the CBI scanner to check whether his company, Green House Promoters, was a conduit for the money generated in the spectrum scam.
CBI officials visited Batcha's house Thursday morning and carried out investigations. Police officers said Batcha hanged himself with a rope on a hook used to tie a baby cradle.
According to police, Batcha left behind a suicide note asking his wife S. Reha Banu to forgive him. He also requested his brother-in-law to take care of his family.
Batcha's wife has said her husband was under pressure because of the CBI's investigation into the spectrum scandal and the media spotlight on him.