A bench, headed by Chief Justice H L Dattu, said the High Court at Hyderabad and the National Human Rights Commission are already looking into the incident.
The petition was filed by an advocate and some individuals who had contended that among the victims were innocent labourers from Tamil Nadu.
The incident came under severe attack from rights activists and political parties including in neighbouring Tamil Nadu.
However, the relatives of the victims said the 20 people were shot dead by the police in cold blood.