Anguished leaders of the Baha'i faith in this country told a congressional hearing yesterday that the present government of Iran is conducting a policy of genocide against Iranian Baha'is.

Displaying color photographs of bloody and mutilated bodies, Los Angeles Municipal Court Judge James F. Nelson, lay head of Baha'is in the United States, told of multiple atrocities suffered by Iranian Baha'is.

He said Iranian Baha'i leaders have been arrested and executed secretly without trials, widows of victims have been forced to pay for the bullets used in executions before they could claim the bodies, and government-approved mobs have attacked Baha'is in their homes, hacking and burning them to death.

Nelson told the House Subcommittee on Human Rights and International Organizations that since Tehran's highest court has ruled that membership in Baha'i assemblies in Iran is "a crime punishable by death," authorities have stepped up their assaults on the leadership of Iran's 300,000 Baha'is. The Iranian government considers them members of a heretical sect.

In other testimony Ramna Nourani, an Iranian graduate student in this country, told how first her father, then her mother, and later several cousins and friends--all leaders in Iranian Baha'i affairs--were arrested and executed or "simply disappeared." All, she said, "were among the cream of the crop of their society. They were among the most educated, they were professionals."

Congressmen attending the hearing, part of an ongoing series on religious freedom around the world, expressed frustration about what this country could do to bring pressure on Iran.

"Baha'is in Iran actually face extinction," said Rep. Edward J. Derwinski (R-Ill.). "We have very little leverage today" with Iran; "very few governments have any leverage. Until we can find some leverage there is probably not much we can do."