Bangor police responded to a residence on West Broadway Monday afternoon to investigate a suspicious letter.

The residence is that of U.S. Sen. Susan Collins, R-Maine, and her husband, Tom Daffron.

A spokeswoman for Sen. Collins said the person that wrote the threatening letter claimed it was contaminated with ricin. Ricin is a highly potent toxin that recently had been used in attacks on the Pentagon and the White House.

"Senator Collins’s husband, Mr. Daffron, their dog, and parts of their home were quarantined while the crime lab undertook an analysis of the premises," Annie Clark, spokeswoman for Collins, said in a statement Monday night. "The affected areas have now been cleared, and Senator Collins and Mr. Daffron will be able to remain at home Monday night."

Members of the Criminal Investigation Division, the Bangor Fire Department and a HAZMAT team from Orono Maine are assisting the investigation.

The call was received at 1:39 p.m.

In a news conference, Bangor Police Sgt. Wade Betters said they had no information to suggest the public was in danger.

Collins has lived in Bangor for many years, moving from her home on Nowell Road to West Broadway in 2013.

Collins came under intense scrutiny following her vote to confirm Brett Kavanaugh to the U.S. Supreme Court.

Collins and Daffron released the following statement in response to the incident.

"We are very grateful for the immediate and professional assistance that we received from the Bangor Police Department, the Maine Crime Lab, the Maine State Police Department, the Capitol Police, the FBI, the Orono Hazmat Unit, the Bangor Fire Department, the U.S. Army, and the U.S. Postal Inspection Service. We are also truly appreciative of the many well wishes that we received today. Our friends and neighbors have been incredibly kind and have even offered to open their homes to us. We feel blessed to live in such a supportive community."