"It (viscera) will be sent abroad, the decision will be taken in one or two days," he told reporters outside Delhi Police Headquarters here.
Delhi Police had on January one registered a case of murder in connection with Sunanda's death under Section 302 of IPC on the basis of an AIIMS medical report that concluded that her death was unnatural and due to poisoning but did not reveal the nature and the quantity of the poison.
A Special Investigating Team has also been formed to probe the case from scratch.
On January six, Bassi had said that it was necessary for them to file an FIR to be able to send viscera samples abroad to determine the nature and the quantity of the poison. The samples will be sent to a lab either in the US or UK but the final decision has not been taken so far.
Asked when Congress MP Shashi Tharoor will be questioned in the case, Bassi said the SIT is working as per a definitive action plan and what is necessary is being done.
"As and when they need to examine a particular individual, they are calling the person. I am sure they will not leave anything uncovered in this investigation," he said.
The police chief maintained that their objective is to complete the investigation at the earliest as possible so that we can come to a logical conclusion.
Questioned whether the SIT wants to confront Tharoor with the statements of other individuals in the case and the available evidences, Bassi said that he will not like to prejudge what the SIT is going to do.
"But I can assure you that the SIT is proceeding in a very scientific fashion. Many things have been written and spoken (in the media) which may or may not be correct...Bear with us, maybe I will be able to tell you something in the next two to three days," he said.
Asked when a charge sheet would be filed in the case, he said, "We will be coming to a final conclusion and whatever would be necessary on merit will be done."