Reports have indicated there is evidence that might tie bin Laden to the attacks Tuesday on the World Trade Center in New York and the U.S. Pentagon in Washington, D.C..
Sellers said he does not have any information on the link to Bin Laden, reportedly living in Afghanistan. He said even if he did, he could not release it.
Sellers said the FBI would not make statements naming any suspects "without something being there."
His comments came as federal authorities, following thousands of leads, started to unravel ties bin Laden has in the Boston, including family members and associates who lived in that city.
The two hijacked airliners that plunged into the World Trade Center departed from Boston.
Investigators were starting to identify suspects from the airline passenger manifests, according to reports, and were questioning flight schools in Florida where some of the hijackers may have trained.
Sellers said Wednesday such leads will be a crucial element to the case, adding even his office has received reports and agents here will follow leads. He did not speak in detail about any leads.
Still, he said, "You would be surprised at the tidbits of information that can affect the case. Every lead is a potential key that solves the case."
Sellers said agents based locally are ready to go to New York or Washington if FBI headquarters determines more support is needed.
"We would like to be there contributing to the effort," Sellers said.
He said of the probe, "It's going to take a lot of time. It could be months, it could be years. I suspect the agents are going to need relief."
Sellers described a painstaking process facing FBI agents heading the investigation and all others taking part in the effort.
He said agents are going to have to go through each piece of the rubble to try to find evidence that could be used in court to prosecute anyone tied to the attacks.
"It's like putting a jigsaw puzzle together," Sellers said. "You try to put the pieces together to get the big picture. You try to find each piece to bring out the picture."
He added, "The whole goal, the final product is prosecuting who did this and you do that with evidence, and that evidence has to stand up in court."
When asked if the FBI's investigation could lead the United States to pursue military action, he said, "Our focus is prosecuting the perpetrators of the crime. We are not in the business of declaring war. It is not our job to seek retribution."
Sellers was asked if the terrorist attack will require the use of all FBI resources.
"If they need the entire bureau to work this, then that is what they will do," he said. "They will use whatever resources are necessary to get this done."
Still, he said there are other crimes to be solved and that cannot be forgotten.
While Sellers said in his line of work one sees "the bad side of people more than others," the crime against America still shocked him.
He said FBI agents receive training on dealing with terrorist acts, but he said the actions Tuesday are still overwhelming.
Sellers said to keep from being overwhelmed by the magnitude of such a probe, agents cannot let the work consume them.
"It is a matter of personal discipline to just kind of turn it off, go home and not think about it," he said.
Asked if the perpetrators of the attack can be captured, Sellers said, "We will make every effort to catch whoever is responsible."
However, he added, "I would be naive to say every criminal out there gets caught. There are no guarantees in life, but every effort will be made."
He said the cost both financially and psychologically will be significant for the country.
Staff Writer Darren Simon can be reached at 337-4082.
The Associated Press contributed information to this story.