By DANIEL J. WAKIN

Salahuddin Mustafa Muhammad, the imam at the Masjid al-Ikhlas, a mosque in Newburgh, N.Y., has spent more than two decades ministering to the Muslim faithful in prisons, serving as a chaplain at the nearby Fishkill Correctional Facility. There, he leads prayers and offers counseling.

“Most people are searching,” he said of the men he encounters in prison. “So they decide on Islam and that becomes their life.”

But last week, Mr. Muhammad found himself an accidental actor of sorts in the latest case of what the authorities call a homegrown terror plot, one in which four ex-convicts were accused of trying to blow up two Bronx synagogues and attack military aircraft. The plot, the authorities say, began when one of the men met a government informant at Mr. Muhammad’s mosque roughly a year ago.

With at least two of the men appearing to be prison converts to Islam, the case has in certain circles evoked an old debate about the role prison might play as an incubator of extremist ideas among Muslims, and it put Mr. Muhammad in the position of confronting that debate in a very personal way.

Mr. Muhammad said his years working with Muslims in prison had turned up little actual evidence that many or any of them became radicalized behind bars.

“I don’t hear any of that wild stuff,” he said. “And if I did hear it, I would stomp it out. It is totally un-Islamic.”

The authorities have made no overt claim that the four suspects — James Cromitie, Onta Williams, David Williams IV and Laguerre Payen — hatched a plot in jail or that their experiences behind bars led to their alleged acts. In fact, it is uncertain just how much of a role their faith played in their motivation.

What is clear is that the men were all initially described by the authorities and some family members as Muslim, and all had served time in prison. In the case of Mr. Cromitie, he even served time at the Fishkill Correctional Facility in Beacon, N.Y. — the very prison where Mr. Muhammad works. He also was said to have occasionally attended the mosque in Newburgh, where Mr. Muhammad serves as imam.

Mr. Muhammad said he did not know Mr. Cromitie from prison. He said a former Fishkill inmate who did know Mr. Cromitie said he did not take part in the Muslim circle there. Maybe 300 to 400 inmates there are on record as Muslim, but only about 150 regularly come to services, he said.

Other Muslim prison chaplains sought to quash the idea that prison, where most of the Muslims are African-American, breeds Islamic extremism.

“Guys in prison are no more vulnerable than other people in society,” said Imam Talib Abdur-Rashid, a chaplain in the New York City prisons who is also the imam of the Mosque of Islamic Brotherhood in Harlem. “These are just isolated cases. The direction of Islam in prison remains reformation and community upliftment and that type of thing.” He continued, “If the guy was an unreformed sociopath who happens to be a Muslim, that’s the case. His Islam is not to blame for his condition.”