The non-arrest of the MP so far is leading to several doubts and the delay in his arrest would impact the probe in the murder case, PMK founder-leader Dr S Ramadoss said in a statement.
The Lok Sabha MP from Cuddalore has been named in an FIR in the murder of Govindarasu, an employee in his cashew unit off Panruti in Cuddalore district of Tamil Nadu.
While five men including Ramesh's assistant have been arrested, the MP, who is the prime accused has not been arrested yet, the PMK leader said.
Ramesh would have been under police's watch following the murder of the worker last month and there is no difficulty in zeroing in on his location.
Under such circumstances, "why is the CB-CID hesitant in arresting the prime accused Ramesh? This is not known," the PMK leader said, adding without arresting the MP, there was no use in arresting others.
Ramadoss alleged that if not arrested, Ramesh would tamper with evidence and urged the CB-CID to immediately arrest him.
Ramesh has been booked under various sections of the IPC including murder, wrongful restraint and conspiracy and for causing disappearance of evidence and CB-CID is probing the case.
Govindarasu, a PMK office-bearer had been working in the cashew nut unit owned by Ramesh in Cuddalore district for the past about seven years.
The cashew nut unit management had claimed that "Govindarasu died by suicide" and initially police probed it as a "death under suspicious circumstances". Later, the case was taken up by the CB-CID and the issue also went to the Madras High Court.