Prosecutors say Pecker's actions helped Trump deceive voters in the 2016 election
She claims the arrest is part of the Awami League's ploy to hold on to power.
Roy was arrested on Friday morning over an attack on ruling Awami League MP Chhabi Biswas.
In a statement on Friday, Khaleda demanded his unconditional release.
A Dhaka court has remanded Roy for three days.
Khaleda alleged the Awami League was "using the law-enforcing agencies and its affiliates to oppress the opposition."
She also criticised alleged police raids at the homes of Roy and BNP metropolitan unit Member Secretary Habib Un Nabi Khan Sohel.
"The government has implicated hundreds of opposition leaders in false cases to divert attention from the Awami League's attack on BNP activists at Bakshibazar," the BNP chief alleged.