Headley, during his testimony before a Chicago court in the trial of his accomplice Tahawwur Rana, had admitted that he did the recce and took photographs of the popular hang-out in Pune, official sources said.
"It is a vital admission and we are considering to make him a co-accused in the charge sheet. We will also press for his extradition in this case," an official, privy to the development, said.
Officials said Headley's extradition should not be an issue in German Bakery case as the Pakistani-American had entered into the plea bargain with the US authorities in connection with the Mumbai attack case.
The government is expecting all relevant documents related to Rana's trial to be received from the United States within the next 15 days.
"After studying the documents, we will take a decision on seeking access to Headley. If necessary, we will send a team to the US," the official said.
At least seven persons were killed and 60 others were injured when a powerful blast rocked Pune's German Bakery on February 13, 2010.