A bomb squad was called to Aylestone Road after a “suspicious package” was delivered to British Gas offices, Leicester Mercury has reported.
Hundreds of people were evacuated from the building and a road in the area was closed while officers assessed the situation.
A spokeswoman for Leicestershire Police said: “A call came in at 10.20am to report that a suspicious package had been delivered to a business.
“In the interest of public safety police evacuated the area.
“All staff from the building were evacuated as a safety precaution.”
She added that staff were directed to the nearest safety point.
She said: “The package has been examined and it was not suspicious. The road has now been re-opened and everything is back to normal.”
Staff will now return to the building following the scare.
Aylestone Road was closed in both directions between Saffron Lane and Grace Road, but re-opened just after midday.