A Connecticut nuclear engineer said he's become enmeshed in a federal terrorism probe -- targeted for supporting a militant Islamic Web site when all he may have done is offer to help humanitarian efforts in a war-torn region.

Syed R. Maswood, 41, a Bangladesh immigrant who became an American citizen in 1997, said his home has been raided and he has been detained and searched three times while traveling on business recently. been placed on a U.S. no-fly list -- a watch list including suspected terrorists, he said.

Maswood, a father of three who has donated to several GOP campaigns and keeps a picture of President Bush (search) in his living room, believes he's being singled out because he is Muslim.

"I believe in this country," he said. "I believe in the system. I believe in the fairness of the law. I want to know, what did I do wrong?"

Maswood confirmed he is the unnamed Connecticut (search) resident mentioned last week in a federal affidavit charging a British national with supporting terrorism. He said federal agents raided his home March 17, seizing computer equipment and financial records.

Investigators discovered the resident's e-mail address among files used to maintain a Web site that funneled money and equipment to terrorists, according to the affidavit, unsealed Friday in New Haven (search) as part of an international terrorism probe.

From his home, Maswood runs North American Technical Services, which exports radiation detection instruments, water treatment devices and environmental equipment to Middle East and Asian governments. He said he's had difficulties doing business through the government since Sept. 11, 2001.

U.S. Attorney Kevin O'Connor would not confirm Maswood is the Connecticut resident mentioned in the affidavit.

"We go out of our way in any case not to identify anybody until they've been charged," O'Connor said. "Unfortunately, there's only one way to search a house and that's in public."

Federal agents last week charged British computer specialist Babar Ahmad with running a fund-raising site for Islamic militants. While dissecting Ahmad's computer files, investigators say they discovered an e-mail seeking help getting money to Islamic rebels in Chechnya.

Maswood said investigators traced an e-mail to him, but added that he's never offered to aid Chechen rebel leaders. He said he may have asked how he could help the humanitarian effort in the area.

Immigration and Customs Enforcement agents also discovered Maswood donated more than $10,000 to the Benevolence International Foundation, an Illinois-based charity accused of supporting terrorism.

Maswood said the charity is one of many he has supported for humanitarian purposes, including Christian relief efforts. He said investigators seized evidence of those donations during the raid.

Before the Sept. 11 terrorist attacks, Benevolence International had been given IRS tax-exempt status.

"If you're claiming that BIF was a terrorist organization, why did the IRS issue them a tax ID number and allow them to solicit donations from all over the country?" Maswood asked.

Last week, a federal law enforcement official, speaking on condition of anonymity, said investigators are going through e-mail addresses uncovered in the Ahmad case, trying to determine who wanted to provide humanitarian aid and who wanted to support terrorism.

"We have known Sayed as a very charitable person," said Ahmad Tansheet of the Muslim Civil Rights Center in Illinois. "His only crime was to give charity to an Islamic organization."

For now, Maswood said the investigation has made him seem guilty to many in Cromwell, a small Hartford suburb. Though he hasn't been named, federal investigators confirmed a search warrant was executed in Cromwell.

In a town of 13,000 people, Maswood said, that effectively identified him.

"I come from a very oppressive country," said Maswood's wife, Awatef, who was born in Tunisia and became a U.S. citizen in 2000. "I used to come back to the U.S. and feel relief. I'm home. This is a free country. What kind of America is this?"

Maswood has sent O'Connor several letters asserting his innocence and characterizing the probe as a witch hunt.

"It's character assassination," he said. "You label them, you destroy their reputation, then later on you may or may not find something."