A team of ACB officials visited Dikshit's residence in Nizamuddin area here and gave the questionnaire on the scam.
"We have asked her to reply to the questions within next two-three days," said a senior ACB official.
Dikshit, however, told the ACB team that she would not be able to reply to the questions immediately and that she needed more time.
The Delhi government had in June sent a report of the fact-finding committee on the scam to Lt Governor Najeeb Jung following which an FIR was registered in connection with the matter.
The ACB then had said that they would question Dikshit in connection with allegations against her relating to the scam.
Dikshit had all along been maintaining that there was no corruption at all in procurement of tankers and that the allegations were "politically motivated".