A hazmat official enters a taekwondo studio previously operated by James Everett Dutschke in Tupelo, Mississippi April 24, 2013. Federal law enforcement agencies investigating ricin-laced letters sent to President Barack Obama and other officials broadened their search for clues on Wednesday by targeting the former business of a Mississippi martial arts instructor. Members of an anti-terrorist response team from the Mississippi National Guard wearing hazmat suits had already searched Dutschke's home on Tuesday, accompanied by agents from the FBI and the US Capitol Police.[Photo/Agencies]

JACKSON, Miss - Federal law enforcement agencies investigating ricin-laced letters sent to President Barack Obama and other officials broadened their search for clues on Wednesday by targeting the former business of a Mississippi martial arts instructor.

Members of an anti-terrorist response team from the Mississippi National Guard wearing hazmat suits had already searched the Tupelo home of Everett Dutschke on Tuesday, accompanied by agents from the FBI and the US Capitol Police, according to law enforcement sources and Dutschke's attorney, Lori Nail Basham.

Federal agents moved their search to the premises of a former martial arts studio Dutschke ran in Tupelo on Wednesday morning, Basham said.

US prosecutors dropped charges on Tuesday against another Mississippi man, Paul Kevin Curtis, who was released from jail after a search of his home in nearby Corinth revealed no incriminating evidence.

Prosecutors said the "ongoing investigation has revealed new information," but provided no additional details.

The National Guard's 47th Civil Support Team is a "full time response team for emergencies or terrorist events that involve weapons of mass destruction or toxic industrial chemicals," according to its website.

Dutschke was cooperating with federal officials, according to Basham.

"We haven't received any information that he has been named as a suspect that I'm aware of. Hopefully we'll know more by the end of the day," she told Reuters. "Mr Dutschke still maintains that he has nothing to do with any of this," she added.

Deborah Madden, an FBI spokeswoman in Jackson, Mississippi, declined to comment.

Dutschke's name first surfaced in a federal court hearing on Monday for Curtis, an Elvis impersonator who was accused last week of sending letters to Obama, a US senator and a state judge, containing ricin, a highly lethal poison made from castor beans.

At the hearing Curtis' attorney, Christi McCoy, suggested that Dutschke should be considered a possible suspect.

McCoy's linking his name in the case was "reckless and irresponsible," Dutschke told the Mississippi Clarion-Ledger.

"It has made my family incredibly unsafe. It has put a target on us," he said.

Dutschke denied having any involvement in sending the ricin-laced letters, said he knew Curtis but only had contact with him three times, but not since 2010.

He told the paper that Curtis had posted a membership certificate for the high-IQ society Mensa online, which Dutschke said was fake.

"I called him out on that in an email confrontation and I've had no contact with him since that, June 1, 2010."

Dutschke was recently indicted in Lee County on three molestation charges, his attorney confirmed. The indictments allege that he fondled three females under the age of 16, according to Northeastern Mississippi Daily Journal.

In 2007, Dutschke ran unsuccessfully as a Republican candidate against Stephen Holland, an incumbent Democratic state representative from the Tupelo area. Holland's mother, Sadie, is the judge to whom one of the ricin-tainted letters was mailed this month.

The ricin letters were intercepted by authorities before they reached their destinations. The poison scare put Washington on edge during the same week the Boston Marathon bombing occurred.  

Typewritten on yellow paper, the three letters contained the same eight-line message, according to an affidavit from the FBI and the Secret Service filed in court.

"Maybe I have your attention now / Even if that means someone must die," the letters read in part, according to the affidavit. The letters ended: "I am KC and I approve this message."

The initials "KC" led law enforcement officials to ask Wicker's staff if they were aware of any constituents with those initials, and the focus of the investigation then turned to Curtis, the affidavit said.