By Paul Kurtz

PHILADELPHIA (CBS) — Investigators are trying to track down burglars who’ve been breaking into condo’s at Waterfront Square at Penns Landing.

Police believe two people on the inside are responsible for four burglaries dating back to August. The most recent happened just before Christmas.

There were no signs of forced entry and the burglars were able to avoid being picked up by surveillance cameras.

A source close to the investigation tells KYW Newsradio that all the victims were Asian.

In each case, the suspects gained entrance to the unit, perhaps by a master key or credit card, picked up a safe and walked out. One of those safes contained around $100,000 in cash. Other items taken included expensive jewelry and watches.

In addition to the police investigation, the Board at Waterfront Square has hired a private investigator. At least three members of the Philadelphia Eagles and a well known boxer own condos at Waterfront.

Calls to Waterfront Square have not been returned.