The SIT had Naveen ride a bike in its custody.
The court has postponed the hearing in this regard to March 12.
Kumar, according to the police official, was a member of a hard-line Hindu group called the Sanatan Sanstha.
She was the most high-profile journalist murdered in years and her killing sparked protests across India, demanding immediate arrest of the assailants. The SIT had found a Kannada translation of a book by Jayanth Athavale, the founder of Sanathan Sanstha and a Hindu alamanac, published by Sanathan Prabha along with Athavale's photograph along with 10 bullets and other items when they raided his residence in Manya and Birur.
Kumar's lawyer Vedamurthy argued that he had been in custody for 20 days, and there was no need to extend it. He was also at the Sanstha headquarters in Goa for several days previous year for a conference. The investigations in the Upparpet case has shown that Kumar, during conversations about guns and ammunition with some of his friends from Maddur, alluded to his links to the murder of Lankesh.
A native of Mandya district about 100 km from Bengaluru, Naveen Kumar was caught by the organised crime wing of the state police's central crime branch on February 18, 2018. "We are not even sure whether Praveen is his real name or not, but we have some definite clues, and efforts are on to track him down", a senior police officer said.
Kumar's family has maintained that he was innocent and in no way connected to the case.
Bhagawan is based in Mysuru. He was taken into custody on March 3 by the Karnataka SIT (Special Investigation Team) for scrutinising. It is said that he has connection with Hindu fringe groups and that he bore resemblance to the person caught on the CCTV, making trips around Gauri Lankesh's house.
Gauri Lankesh was a respected senior journalist and a well-known critic of right-wing forces.