A team of Central Bureau of Investigation (CBI) officers arrived in Tamil Nadu's Madurai.
They arrived at Madurai Airport on July 10.
CBI will take over the probe in Thoothukudi custodial death case.
The CBI had taken over the investigation on July 07 into the deaths of P Jeyraraj and his son J Benicks who died allegedly after being tortured in police custody in Tamil Nadu's Tuticorin.
The Centre had issued a notification accepting Tamil Nadu Chief Minister's request to transfer the probe to the CBI.