Mark Pratt at the Boston bureau of the Associated Press is reporting that state officials have found the same strain of listeria inside the Whittier Farms Dairy processing plant that was responsible for three deaths and a miscarriage. 

The AP says the investigation now has to figure out exactly how the milk came into contact with the deadly listeria.

"We know that there’s a problem in that plant and we have connected the patients to the products to the plant, now it would be nice to know exactly how that happened, but that is part of the ongoing investigation," said Dr. Alfred DeMaria, state director of communicable disease control.

More than 100 samples were taken from inside the plant located in Shrewsbury, MA  and responsible strain of listeria was found in seven bottles and on the floor near the homogenizer .at the Shrewsbury plant.  The AP story can be found here.