At a trial over allegations of Iranian sponsorship of terrorist groups, prosecutors and defense counsel sparred over the nature of a Manhattan-based nonprofit foundation.

Defense counsel said federal prosecutors were trying to impose the “death penalty” on the foundation by pursuing a forfeiture suit to seize its properties to pay judgments to victims of terror attacks by groups sponsored by the Iranian government, an attorney for the foundation argued Tuesday.

Lawyers from the U.S. Attorney's Office for the Southern District of New York portrayed the Alavi Foundation, which is the majority owner of a 36-story building at 650 Fifth Ave., as a witting front for the Iranian government and a vehicle for sanctions avoidance.