REVEALED: Newborn twin boy's body was covered in a pet pee pad in a Bronx alley and had his umbilical cord wrapped around his neck while his brother was dumped in a plastic bag

Gruesome new details have emerged about the newborn twin boys who were found dead in The Bronx on Monday, including how a building superintendent mistook one of them for a doll before discovering the child's body wrapped in a pet training pad.

The shocking discovery was made outside 1460 College Avenue in the Claremont section of The Bronx shortly before 2pm. 

While police previously said the babies were about a week old at the time of their deaths, law enforcement sources have since said they were less that 24 hours old. 

The brothers were found 20 feet apart outside the building. 

Newborn twin boys were found wrapped, one in a pet training pad, the other in a plastic bag, outside an apartment building in the Bronx on Monday afternoon

The horrifying discovery was made by the super of the Claremont building at 1460 College Avenue on Monday before 2pm, hours after he initially mistook one of the babies for a doll

Police said the babies were 24 hours prior. Their deaths have been classified as suspicious

Police said the babies were 24 hours prior. Their deaths have been classified as suspicious

One of the boys had his umbilical cord wrapped around his neck and showed signs of head trauma, while his twin brother was stuffed into a black plastic bag with no apparent injuries, reported the New York Post.  

Police have classified the deaths as suspicious, but they were awaiting the results of the children's autopsies to determine how they died. 

The superintendent of the building who found the children on Monday spoke to the Post, revealing that he first saw one of the babies lying unconscious on the ground at 8am, but he mistook the boy for a doll and carried on about his day. 

'I didn’t pay it any mind, because I thought it was a toy doll,' the man, who gave his name as Johnny, told the paper. 

It was not until nearly six hours later that the superintendent went back outside and realized that it was a baby boy laying on the ground. 

Johnny said that upon closer examination, he found the boy wrapped from the waist up in a blue pet training pad, which was wet with blood. 

A medical examiner will determine the official causes of death, NYPD Deputy Chief Timothy McCormack said at a press conference (pictured)

A medical examiner will determine the official causes of death, NYPD Deputy Chief Timothy McCormack said at a press conference

Police have not speculated about any potential motive or suspects

The deceased children were found behind the building, police said. The front is shown above

A short distance away, the super came upon the body of the twin, who had been placed inside a plastic bag. The man noted that some blood had leaked out of the bag, although police have said the boy's body showed no visible signs of trauma. 

First responders who were summoned to the scene rushed the children to Bronx Lebanon Hospital, where both were pronounced dead on arrival.  

Investigators said earlier they believed the twins were possibly thrown from an upper-floor window. 

A medical examiner will determine the official causes and manners of death, NYPD Deputy Chief Timothy McCormack said at a press conference. He declined to comment on visible injuries.  

Investigators are searching for video, which could show who left the babies behind the building.   

They have not speculated about any potential motive or suspects. The babies' parents are unknown. 

A large police presence was seen outside the building on Monday afternoon in footage from ABC7. 

Police asked anyone with information to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or submit tips online at nypdcrimestoppers.com.