Students Against Discrimination coordinator Nahid Islam, who was instrumental in overthrowing Sheikh Hasina and is now part of an interim government said she must face trial when she returns home as planned for the killings during her term, including during recent protests, which led her to resign and flee on Monday.
About 300 people, many of them university and college students, were killed in the demonstrations that began in July with students demonstrating against quotas in government jobs before spiralling into violent protests to oust Hasina, who had ruled Bangladesh for 20 of the last 30 years.
Hasina's son Sajeeb Wazed Joy has said she will return to Bangladesh from India, where she is sheltering, once elections are announced in her home country, which the main opposition has demanded should be held in three months.
"I am curious why she fled the country," student leader Nahid Islam, who is effectively a minister in the caretaker government, told Reuters late on Friday in his first interview since joining the government on Thursday as an adviser.
"We will seek justice for all the killings that happened under her, which has been one of the main demands of our revolution. Even if she does not come back, we will work towards that."
"We want to arrest her - whether that will work through the regular judicial system or a special tribunal on that or not, we are discussing how to proceed on the matter," said Islam, 26, who now heads the postal, telecommunication and information technology ministries.
Joy, who is based in the United States, did not respond to a request seeking comment. Hasina, who is under the protection of the Indian government, could not be contacted.
Another student leader, Abu Baker Mojumder, separately told Reuters they want Hasina to return and face trial.
Islam said one of the caretaker government's main priorities was to hold a free and fair election, after the last election was boycotted by the opposition, and also investigate suspected corruption in the previous government.
Islam said Bangladesh would need electoral and constitutional reforms before any election, so it was not clear when the next vote would be held. He declined to give a specific timeline.
"My ambition on what I next become depends on the people of Bangladesh," he said, when asked whether one day he would like to be prime minister.
He said India had fostered a relationship with Hasina's Awami League party, but not the people of Bangladesh as a whole.
"We want friendly ties with India," he said. "India also needs to look at its foreign policy, else it will become a problem for the whole of South Asia."