Shastri who preceded present Chairman V R S Natarajan came to the CBI Headquarters in the morning and answered queries of the sleuths till evening, CBI sources said.
Sources said Shastri was questioned on the agreements on technology transfer for manufacturing all-terrain trucks from Tatra which are known to have unique axle technology allowing it to conquer almost any terrain.
The agency is probing alleged irregularities in assigning supply from the Czechoslovakia-based Tatra, with which the agreement was originally signed in 1986, to the Tatra-Sipox UK owned by Rishi in 1997 showing it as Original Equipment Manufacturer and the fully-owned subsidiary of the Czech company, they said.
A CBI spokesperson said this was against the provisions of Defence Procurement Procedure for supplying the vehicles to Indian Army on the basis of the orders placed by the Ministry of Defence.
"It is further alleged that in this manner, vehicles worth thousands of crores of rupees have been supplied to the Indian Army. In continuation of the aforesaid conspiracy to cause undue benefit to the UK-based company, the unknown officials of the Defence PSU allowed change of currency from US Dollar to Euro and further by not levying the Liquidated damages caused further loss of Rs 13.27 crores", the CBI said.