The Supreme Court stated on Tuesday that if a "common thread" were found between the murders of Gauri Lankesh, Govind Pansare, MM Kalaburgi, and Narendra Dabolkhar, then the CBI alone investigate the cases involving the four social activists, according to reports.

The apex court bench, comprising of Justices U U Lalit and Navin Sinha, has reportedly given the CBI until the first week of January to provide an explanation as to why it would not be able to investigate all the four cases if a common link appeared.

After studying the reports submitted by the Karnataka State police, the court determined that there appeared to be a common thread between the murder of Gauri Lankesh and rationalist MM Kalaburgi, according to the Economic Times. The police have also reportedly told the apex court that they would file a charge sheet in the Kalburgi murder within the next three months.

On November 26, the Supreme Court had called out the Karnataka government for its inaction in the investigation and indicated that the case may be transferred to the Bombay High Court, reports say.

MM Kalaburgi, a scholar and rationalist, was killed in 2015 in Dharwad. Social activist and reformer Govind Pansare was murdered the same year as well. Narendra Dabolkhar was killed on August 20, 2013. Gauri Lankesh, an activist and journalist, was killed on September 5, 2017 outside her residence in Bengaluru.

Earlier, the Special Investigations Team (SIT) probing the murder of Gauri stated that four leaders of a pro-Hindutva outfit were the prime suspects of having plotted to kill her and other rationalists. As per a TNM source, six of the accused in the case executed the plot to murder Gauri.