"There can't be fair elections under Sheikh Hasina, not even if the Election Commission wanted one," she told a gathering of pro-BNP engineers in Dhaka on Wednesday.
"Hasina should be ousted to make way for a fair election, if necessary."
The BNP is currently not in parliament after it sat out the 2014 general election following a long failed campaign to return the system of holding elections under caretaker governments.
The party had launched an anti-government campaign to mark a year of the election, which led to a loss of more than a hundred lives in violent blockades and general strikes.
Khaleda during the Iftar gathering at Bashundhara Convention Centre brought up Apan Jewellers, the jewellery brand owned by the family of a high-profile rape suspect. The business has also come under a gold smuggling investigation.
"You can see many things happening with Apan Jewellers. You see investigations get buried once there is exchange of money and gold."
"Now it's quite clear that powerful members of the Awami League are involved in gold smuggling. This is the reason why there is so much gold coming into the country.
"They're only catching a few for eyewash. This is our reality," said Khaleda.