Hyderabad, Telangana's opposition Congress on Friday submitted a memorandum to Governor, Dr Tamilisai Soundarajan, seeking a probe by the Central Bureau of Investigation (CBI) into the killing of advocate couple.

A delegation of party leaders led by state party chief Uttam Kumar Reddy met the Governor at Raj Bhavan and submitted her a memorandum for a court-monitored CBI probe into the gruesome murder of Gattu Vaman Rao and his wife Nagamani, who were practicing at the Telangana High Court.

The couple were waylaid and brutally hacked to death in full public view by two assailants in Peddapalli district on February 17.

Police have so far arrested four accused including a mandal-level leader of ruling Telangana Rashtra Samithi (TRS), who has been since suspended from the party, and the nephew of another TRS leader and Zilla Parishad chairman Putta Madhu.

Reddy, who is also a Member of Parliament, alleged that the murders are an attack on the legal community to silence them and "prevent them from exposing the massive corruption and misuse of state power".

The Congress leader alleged that the advocates were murdered to prevent the truth from coming out in the death of Seelam Rangaiah, a Dalit, in police custody.

Reddy told reporters that the Governor responded positively to their demand for the CBI probe.

Alleging that the ruling party leaders are involved in the murder, he said the police were not probing their role.

The state Congress chief said the couple was killed in a pre-planned manner as they had approached the High Court for justice in Dalit youth's death in police custody and they were also proving hurdle for TRS leaders' illegal activities in Manthani.

Reddy claimed that Vaman Rao was silenced as he was gearing up for a fight over illegal mining of sand worth Rs 4,000 crore from the Kaleshwaram lift irrigation project.

He said Vaman Rao was also exposing the Putta Lingamma Charitable Trust for illegally mobilising funds.

The High Court, which took suo moto cognizance of the double murder on February 18, directed the government to conduct thorough investigation and submit a status report by March 1.