A 5-year-old girl disappeared in an area searched as part of the hunt for Madeleine McCann.
The family of Spanish Mari Luz Cortes fear she has been snatched.
Her father, Juan Jose, broke down in tears and said: “Whoever has her, bring her back and everything will be okay.”
The area in Huelva, Spain, which borders Portugal, has been searched by 100 police officers and 500 volunteers.
Search teams are also hunting on the Portuguese side of the border.
Mari Luz went out to buy a packet of crisps from a local shop on Sunday afternoon.
She was last seen by the shopkeeper at around 5pm.
Her family raised the alarm at 7.30 p.m. after searching the area themselves.
Cortes who runs a small construction company, said: “We have no quarrels with anyone. We suspect nobody and everybody because the family doesn’t know how to deal with this situation.
“If anyone has taken Mari Luz by mistake or if they thought she was lost, please bring her back.
“She’s never left home because she’s very shy, and she never gets lost.”
Mari was wearing a jumper and pink leggings and white boots when she went missing.
Huelva is just two hour's from Praia da Luz, the Portuguese resort where Madeleine McCann went missing on May 3, last year
Gerry and Kate McCann visited the city on Aug. 3, as part of their campaign to find their daughter.
The couple, both 39-year-old doctors from Rothley, Leicestershire, believe their daughter was abducted.
Private detectives hired by the couple are investigating paedophile gangs based in Spain, it emerged this week.
They are concentrating their investigation in Valencia and Alicante on the south east coast.