According to the investigation agency, Venkatramana played a key role in allocating land to VANPIC, a company owned by industrialist N Prasad when Jagan's father YS Rajasekhara Reddy was the Andhra chief minister.
Prasad too was taken into custody on May 16.
Prasad is named as the 12th accused among 74 in the first information report filed by the CBI in August last against Jagan and others.
Prasad is alleged to have invested money in Jagan's holdings and the CBI believes this was a way of returning the favour for the land that was allocated to his company. It is alleged that Venkatramana had played a key role during the cabinet meeting when the land was allotted. He was then the investment and ports and infrastructure minister.
The arrest gains importance as it comes a day before Jagan's questioning by the CBI. Venkatramana was questioned by the CBI on Wednesday and Thursday following which he was arrested.
