The parents of the child woke to find their daughter missing from their hotel room in the city of Florencia. After launching a desperate search to find their baby, her body was found shoved inside one of the hotel's water tanks.
A man has been arrested by local police who refused to release his identity.
Police believe the suspect was also staying at the hotel.
Hotel owner Jose Hernandez admitted the security guard in charge of the area had fallen asleep on duty.
Law enforcement in Colombia have chosen to keep all identities of those involved confidential. The parents are receiving counseling.
Psychologist Karen Abudinen said: 'It is a harrowing situation that the young mother is going through, that is why we are not going to leave her for a single moment while she tries to come to terms with it.'