The K Chandrashekar Rao-led Bharat Rashtra Samithi faces big questions as shocking allegations of state police officers tapping the phones of then Opposition leaders, including current Chief Minister Revanth Reddy, celebrities and businessmen come to the fore.
The surveillance, it is alleged, was also used to blackmail businessmen into contributing huge amounts to the BRS party fund.
The BRS is yet to respond to the allegations.
Three senior police officers have been arrested in this connection and a lookout notice issued against T Prabhakar Rao, former chief of the state intelligence bureau, who is reportedly in the US now.
Police have said two senior officers - Additional Superintendent of Police Bhujanga Rao and Additional Superintendent of Police Thirupathanna - have admitted to illegal surveillance and destruction of evidence.
According to reports, Ravi Paul, a technical consultant with the state intelligence bureau under the then BRS government, had allegedly helped import and set up phone-tapping equipment near the residence of Mr Reddy to listen in on his conversations.
The equipment, it is alleged, was imported from Israel using a software company as the front. No permission from the Centre - a must for such imports - was taken, it is learnt. With this setup, anything spoken within a range of 300 metres could be heard, reports say.
Ravi Paul, it is alleged, set up an office near Mr Reddy's residence and installed the device. Police are set to question him in this connection.
Lookout notices have also been issued for Sharvan Rao, who runs a Telugu TV channel I News, and Radha Kishan Rao, a police officer with the city task force.
The surveillance was not restricted to Opposition leaders. Top businessmen, including real estate dealers and jewellers, and celebrities were also under surveillance. In fact, the tapping of phone conversations led to the divorce of a celebrity couple, reports say.
To add to the BRS's troubles, Chief Minister Reddy has received a complaint from Sharan Chaudhary, a businessman and a BJP leader, alleging that senior police officers kidnapped him last year and forced him to sign off a plot of land to a relative of former minister and BRS leader Errabelli Dayakar Rao.
Mr Chaudhury has alleged that Radha Kishan Rao and senior police officer ACP Umamaheswara Rao kidnapped him on August 21 while he was on his way to office. He has alleged that he was illegally detained and forced to register his property in the name of Vijay, a close relative of the minister. He was also forced to pay Rs 50 lakh before they let him go.
The businessman has said he had approached the High Court after the incident, but Uma Maheshwar Rao threatened to file false cases against him and forced him to withdraw the petition.