An invitation to a peace conference from a Catholic group is what prompted the scare at Congressman Peter Welch's office in Burlington after a worker thought the letter looked suspicious.
Authorities locked down the building Monday while a hazardous materials team investigated.
The incident followed the weekend arrest of a Mississippi man accused of mailing letters containing the poison ricin to President Obama and to Sen. Roger Wicker of Mississippi.
Police say the letter to Welch did not contain any dangerous material.
Police said the employee was concerned about "peculiar characteristics" and "notations on the outside of the letter that were unusual."
The Burlington Free Press reports the envelope indicated it was sent from the Fatima Center — Servants of Jesus and Mary, located in Constable, N.Y.
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