At City Hall in Jersey City, a photo of Tim Tebow was found inside an envelope that also contained powder.

A letter to Jersey City Mayor Steven Fulop containing white powder -- and a picture of former New York Jets quarterback Tim Tebow -- caused the evacuation of City Hall today and although harmless, it was clearly meant to look like a chemical or biological threat.

Jersey City Public Safety Director James Shea said the letter was addressed to “Steven Fulop, family and friends.” When it was opened by a mayor’s aide at 2:15 p.m. a small amount of white powder fell out.

Shea said there was a note in the envelope but would not reveal what it said, saying the matter was still under investigation.

A source said the letter contained “spiritual stuff. Heaven stuff. A picture of Tebow.”

Tebow, a first-round draft pick in 2010, was widely considered a bust with the Jets after his signing in 2012 made back-page headlines. The quarterback, who has been outspoken with his religious beliefs, is not currently on any NFL team.

The shocked aide quickly called police, triggering a response from police, the fire department, the city bomb squad, the hazmat unit and ambulances that circled city hall. Shea said those in the room where the envelope was opened were segregated and all others in the building were evacuated.

Two tests performed on the powder revealed it was harmless and by 3:15 p.m. City Hall workers were called to the building’s steps where they were told the good news was the powder is harmless and the bad news was they had to go back to work.

Shea said the matter remains under investigation and police will attempt to determine who sent the envelope. Investigators assume the return address on the envelope is false.

“There have been many of these cases of white powder across the country,” Shea said. “Anyone in the news draws the attention of all kinds of people.”

Fulop was not in the building when the envelope was opened and he responded directly to the city’s Office of Emergency Management on Summit Avenue when police learned of the incident.

Further testing will be performed on the powder to determine what it is.