An attorney for a mosque leader accused of plotting to obtain a shoulder-fired grenade launcher said he may defend his client by arguing that authorities entrapped him.

Yassin Muhiddin Aref (search), 34, was arrested Thursday and charged with aiding a government informant in a fake plot to buy the weapon to assassinate a Pakistani diplomat.

Aref is the imam of the Masjid As-Salam mosque in Albany. Also arrested was Mohammed Mosharref Hossain (search), 49, one of the mosque's founders.

They were arrested as part of an FBI sting operation; the Justice Department (search) says the informant led them to believe they were taking part in the purchase of an RPG-7 grenade launcher for the assassination of Pakistan's ambassador to the United Nations.

"I'm very skeptical about the government's case," Aref's lawyer, Terry Kindlon, said Friday. "My initial reaction is that entrapment is going to be our defense at trial."

Aref, a native of Kurdistan, and Hossain, who is from Bangladesh, face up to 70 years in prison if convicted.

The informant, a Pakistani immigrant, was working for the FBI in an attempt to reduce his own sentence for document fraud.

A close friend of the men, Abdul Shuaib, was among several witnesses subpoenaed Friday to testify before a grand jury. Shuaib said he told grand jurors that Hossain approached the informant because Hossain needed money, and Aref offered to be a witness to their transaction.

Shuaib, 53, said he did not recall the informant telling Hossain that he imported weapons from China, as alleged in the FBI affidavit.

"I was at this particular meeting. I don't recall the word China being used," he said.

Also Friday, two law enforcement officials speaking on condition of anonymity said that documents found last summer by U.S. soldiers at a terrorist camp in northern Iraq referred to Aref as "the commander" and included his address and telephone number in Albany.

The men's wives and fellow mosque worshippers denied the two were involved in any wrongdoing.