The Congress, say sources, has urged its lawmakers to install an app that allows the recording or tracking of calls.
Anand Singh, 52, has been MIA since Tuesday, the day of the Karnataka results. He is one of the 78 Congress legislators elected to the 224-member state assembly.
Janata Dal Secular leader HD Kumaraswamy today alleged that Anand Singh was under pressure from the BJP.
"Modi government is misusing institutions of the central government. I know they are threatening MLAs. A Congress MLA told me Anand Singh called him and told him 'they are using ED (Enforcement Directorate), I had a case in ED and they are going to screw me. I'm sorry I have to protect my interest'," Mr Kumaraswamy said, quoting Anand Singh. Yesterday, he had alleged that Rs 100 crore and cabinet positions were being offered to his lawmakers.
The Congress and the JDS together staked claim to power with 116 lawmakers, but the governor last evening invited the BJP, which won 104 seats but is eight short of the majority mark of 112.
Anand Singh faces charges of illegally transporting iron ore. He was arrested in 2013 and released on bail two years later.
Anand Singh was in the BJP and also a minister in its government before he joined the Congress in January. He was known to be close to the Reddy brothers of Ballari, who are associated with the BJP, and also their aide B Sriramulu.
Mr Sriramulu, who has been elected as a BJP candidate, told NDTV, "We are confident of making the majority 100 per cent. We will prove numbers - hum try karenge (we will try)...We are in touch with like-minded MLAs."
To "protect" its flock from inducements or any attempts to engineer defections, the Congress booked a bus and checked its MLAs into the Eagleton resort near Bengaluru. They are expected to be flown out of Karnataka but only when they know whether the Supreme Court will order a floor test earlier than the 15 days given by the Governor.
Another Congress lawmaker, Pratapgouda Patil, was not on the bus last night.
Pratapgouda Patil, 63, describes himself as an "agriculturist" and was famously dubbed the "poorest" legislator in Karnataka in the previous election.
Yesterday, he was present during the morning headcount when all lawmakers had to sign on a list. Then he vanished.
Independent MLA R Shankar is with the Congress, for now. But he remains a flight risk. In the past two days, he has gone back-and-forth almost faster than one could say Karnataka.