The Central Bureau of Investigation has sought the statement of businessman Abhishek Verma's associate C Edmond Allen in connection with alleged bribe $530,000 he took from Rheinmetall Air Defence AG.
CBI sources said the agency has written to Allen to provide his statement but it is yet to hear from him.
The CBI, which is planning to complete the probe and file a chargesheet by next month, has booked Verma and his Romanian wife Ancia Neascu. Both are in judicial custody.
The sources said Allen's statement would be an added help in corroborating the claims made by the agency and would bolster the case of the CBI. They, however, said the agency has gathered enough material evidence which indicate alleged culpability of Verma in the case and would be sufficient to prove charges against him.
The case relates to $530,000 that Verma allegedly took from RAD on the promise that he would use his influence to stall blacklisting proceedings initiated by the government against it after the Ordnance Factory Board scam had surfaced.
United States-based attorney Allen, who has majority stake in Ganton USA and Ganton India companies alleged to be the front of Verma, had approached the CBI director and other top officials alleging Verma received funds from RAD for bailing it out, they said.
Meanwhile, the agency is also likely to send Letters Rogatory to Switzerland seeking details of RAD, which is based in Zurich, they said.
Recently, Verma had moved a Delhi court with a complaint against his former partner Allen accusing him of cheating him of Rs 55 crore and forging documents and emails to defame him.