Police in Menlo Park are investigating three separate thefts of copper wiring this month from the future headquarters of Facebook.

On June 17, construction crews reported that more than 1,000 pounds of copper wiring was taken from one of nine vacant buildings on the 57-acre campus, located at 312 Constitution Drive, police spokeswoman Nicole Acker said.

It is believed that the wiring was extracted sometime between June 7 and June 13, Acker said.

Three days later, a second load of more than 1,000 pounds of copper wire was reported stolen from a storage unit at the site that was being used by a construction contractor, Acker said.

Investigators believe the wiring was removed sometime between June 17 and June 20.

A third theft of several hundred feet of wiring occurred at another vacant office building on the site on June 22, Acker said.

The total value of all the stolen copper is estimated at about $8,500.

There are no suspects, according to police.