The CBI on Wednesday carried out searches at three locations in Noida and the national capital in connection with its probe into alleged irregularities in the procurement and supply of Tatra all terrain vehicles to the army.

Three teams of the agency officials reached residences of two retired army officials and an official of Vectra early on Wednesday morning and took into their possession some crucial documents related to the deal, the CBI sources said.

The CBI has again called BEML chairman VRS Natarajan and Vectra chairman Ravinder Rishi for questioning, they said. Both were questioned on Tuesday as well.

The agency has registered a case naming Rishi and unnamed officials of the defence ministry, army and BEML on March 30 for alleged criminal conspiracy, cheating and also under relevant sections of the Prevention of Corruption Act.

The agency is probing alleged irregularities in assigning of supply from 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 an original equipment manufacturer and the fully-owned subsidiary of Czech company, which was against the provisions of Defence Procurement Procedure, the sources said.

"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, thereby causing further loss of Rs. 13.27 crores," the CBI spokesperson had said.