Three babies abandoned on three separate occasions at the same apartment complex in Orlando, Florida, have the same biological parents.

Orlando Police Department investigators confirmed on Tuesday that the three babies found at the Willow Key Apartments in 2016, 2017 and 2019 shared the same mother and father.

The findings were first revealed in a memo from detectives seeking funding to analyse DNA of the three children in an effort to track down their missing parents.

Orlando detective Ghena Wasserman Luker wrote that the analogous manner in which all three children were abandoned on a resident's stoop at the Arnold Palmer Drive luxury apartment complex made police believe they must be related.

"A note discovered at the scene explained the baby was left at the location because the mother was in fear of the child's father," Det Luker wrote of the 2019 baby. A similar note was left with the newborn abandoned in 2017.

"Based on the egregious and neglectful behaviour of the parent(s), and the bizarre facts of this case, unlike any other documented case, it is imperative to conduct a well-being check of all involved parties. This cannot be done without the assistance of United Data Connect."

City commissioners approved the $5,000 funding on Monday to hire United Data Connect, which maintains a database of DNA profiles, to track down the parents.

While initial testing had identified several possible family members of the babies, more specialised knowledge from a genetic genealogist was needed to interpret the DNA and determine the parents.

Orlando police said in a statement on Tuesday that while the three infants were confirmed to be siblings, no other details could be shared to protect their identity.