The CBI says that it would like to seek some clarifications from Dr Singh.
The CBI is also likely to question former officials in then Prime Minister's Office.
On Saturday, former Air Chief, S P Tyagi had told a court that the then Prime Minister's Office was in the know of changes in specifications for the purchase of the VVIP choppers.
Tyagi and two others had been arrested by the Central Bureau of Investigation on Friday.
All three were remanded in CBI custody till December 14.
Tyagi was accused of reducing the ceiling height to facilitate the deal.
Under the scanner:
An official with the Central Bureau of Investigation said that they will be sourcing records from the PMO to ascertain details regarding the deal.
We are trying to find out who had leaked information which in turn facilitated the chopper deal.
The CBI is also planning on questioning several others who were part of the government and were in the know of the Rs 3,600 crore deal.
The officer said that the statements made by Tyagi in court are being considered seriously.
Moreover we have also gone through at least 1.5 lakh documents that have come from Milan, Italy which have ample information.
The papers clearly show who was involved in the deal, the officer also said.
On Saturday the CBI's counsel had told the court that Tyagi had given a step by step progress of the case to European middlemen Guido Haschke in connection with the AgustaWestland case.
While seeking Tyagi's custody, the CBI further stated that the latest Letter Rogatory from Mauritius and Italy have startling details which cannot be shared now.
During the court proceedings on Saturday.
Tyagi had said that changing the specifications was not his decision alone.
It was in 2003 that the PMO had told the Air Chief to get involved in the procurement of the VVIP choppers.
It was during a 2005 meeting that the changes in requirements were suggested, Tyagi also said.
The CBI had earlier recorded the statements of M K Narayan who was the National Security Advisor, B V Wanchoo, the former head of the Special Protection Group and E S L Narasimhan, the former Intelligence Bureau Chief.
All these persons are said to have been part of the 2005 meeting in which the change in specifications were suggested.