Azam Khan, 78, walked out of Rampur jail on Saturday after a bail order, only to be seized by the Enforcement Directorate outside the prison gates.
The ED cited the Prevention of Money Laundering Act and alleged PAN fraud, attaching Khan's land and building at Mohammad Ali Jauhar University earlier this week.
On Thursday, the Allahabad High Court suspended the sentence against Khan and his son Abdullah in the dual PAN card case, granting them bail.
Khan's supporters shouted slogans outside the jail, while a heavy contingent of central paramilitary and police personnel maintained order during the detainment.
The ED has registered 58 FIRs against Khan, and officials say he may soon be remanded in a special court in Ghaziabad.
Khan will now appear before the Ghaziabad court, where the agency seeks to secure his remand under the PMLA, setting the stage for a legal showdown.