MIAMI – The suspicions airport security officials had when they saw the metal canister grew when they learned about the man who brought it in from the Middle East: a scientist who sparked a bioterrorism scare after he reported missing vials of plague samples seven years ago.

Officials shut down most of Miami International Airport overnight, roused nearby hotel guests from their beds and detained Dr. Thomas Butler until Friday morning, when he was released without charges, a senior law enforcement official said. The official spoke on condition of anonymity because he wasn’t authorized to release the information.

Tests on the canister found nothing dangerous, according to a statement from the FBI’s Miami field office. Homeland Security spokesman Nicholas Kimball said the item resembled a pipe bomb.

Butler’s former lawyer said the incident appeared to be a “fantastic overreaction.”

Butler, 70, is a world-renowned plague researcher who quickly became the focus of a federal investigation in 2003 when he reported that 30 vials of plague samples possibly had been stolen from his Texas Tech University lab.

He was later acquitted of smuggling and illegally transporting the potentially deadly germ and of lying to federal agents about the missing vials. Jurors found Butler guilty of the mislabeling and unauthorized export of a FedEx package that contained plague samples he sent to Tanzania.

He was also convicted of fraud and theft and sentenced to two years in prison for defrauding Texas Tech about illegally negotiated contracts he had with pharmaceutical companies with which he also had clinical studies contracts.

The senior law enforcement official told the AP that a Transportation Security Administration inspector noticed an odd container Thursday around 9 p.m. as Butler was going through customs. He had arrived on a flight from the Middle East, where he had been teaching at a Saudi Arabian university.

The inspector ran Butler’s name through a database and discovered that he had been tried on the plague-related charges. Officials decided to evacuate the airport and detain Butler, who cooperated fully, the law enforcement official said.

A Miami-Dade police bomb squad spent hours scouring the airport. Between 100 and 200 passengers were evacuated from four of the airport’s six concourses. Airport roadways and a hotel near the airport’s international terminal were closed down. Police and airport officials described the shutdown of the concourses as a public safety precaution.