Jethwa has been charge sheeted under Section 120 B (criminal conspiracy) and Section 320 (murder) of Indian Penal Code, official sources said.
The charge sheet was filed in a special CBI court here.
Solanki, Lok Sabha member from Junagarh, was arrested on November 5 in connection with the case.
Gujarat Police had arrested six persons, including Shiva Solanki, nephew of the BJP MP, and sharp shooter Sailesh Pandya who had shot at Jethwa outside the Gujarat High Court. All of them were questioned by CBI inside a jail after taking permission from the designated court.
More From This Section
The BJP MP was earlier given a clean chit by Crime Branch of Gujarat Police prompting the father of the deceased to approach the Gujarat High Court. Gujarat Police's crime branch had ruled out any involvement of Solanki in the murder.
Terming the probe conducted by the Gujarat Police "far from fair, independent, bona fide or prompt", the High Court had transferred the case to CBI.
The killing had sparked an uproar among RTI activists across the country who raised concerns over the safety of such whistleblowers.
The court had said the probe in the case was "far from fair, independent, bona fide or prompt".
"It has come on record that Shiva Solanki and DB (Dinu Bogha Solanki) were living together in a joint family and no investigator could have been easily satisfied with the statements that they did not interact in respect of the conspiracy to commit a capital crime," the court had said.
Jethwa had filed several petitions in the Gujarat High Court, including a Public Interest Litigation, in connection with illegal mining in Gir forests in Junagarh district which is a protected area and last home to Asiatic lions.