Maliki last year called for the arrest of Vice President Tariq al-Hashemi on allegations Hashemi he was overseeing a death squad. The move coincided with political flare-ups that prompted a major Sunni-backed political alliance to suspend participation in the Iraqi government.
Hashemi told CNN from the semi-autonomous Kurdish region of northern Iraq that Maliki was forcing the country toward sectarian war.
"Maliki is pushing my country to reach a turning point with (a) deeply sectarian dimension," he said.
Hashemi has been hiding in the Kurdish region to avoid arrest. An official in his office, who spoke with CNN on condition of anonymity, said evidence against the vice president was extracted from his bodyguards under duress.
The Sunni-bloc, Iraqiya, had said some of its members would return to the legislative assembly to prepare for a later national dialogue. A Cabinet boycott remains in place, however.
Violence has escalated in Iraq since U.S. forces left the country last month. Victoria Nuland, a spokeswoman for the U.S. State Department, said Iraq has been through "these cycles" before but Washington has confidence "in the Iraqi security forces (ability) to manage these issues."