The bodies of two infants discarded in a field in Kensington were used as medical specimens, the Philadelphia Medical Examiers Office has ruled. 

The bodies, one male and one female, were found in a field in Kensington on Sunday morning by police.

Police revealed late Sunday that the infants had already had autopsies performed on them before they were found in the field — and that they were searching for a black pickup truck seen dumping trash in the area as the possible source of the dead babies.

The bodies had been preserved, said Medical Examiners Office spokesman Jeff Moran. 

But where they came from, how long they had been preserved for, and why they were simply discarded is a question police are still investigating. 

Police made the grim discovery after they were called to the 1800 block of Palethorpe Street, three blocks east of the Berks Station on the Market-Frankford Line around 10:30 a.m. on Sunday.

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There police met witnesses who had been notified by two young boys that they had found the bodies in the field, reports say.

The boys, aged 9 and 12, reportedly told their parents they found the bodies on Saturday evening — but the parents did not believe them and thought they may have been dolls. After the boys told their parents on Sunday that the bodies were beginning to stink, police were called.

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"While processing the scene, Medical Examiner (ME) discovered the corpses had an autopsy performed on them by unknown medical personnel at an unknown time," police said. "However, at this time the ME is unable to provide an approximate age for the corpses at this time."

Police are now seeking video surveillance of the pickup truck that witnesses saw dumping trash on the road near where the babies were recovered.