A post-mortem examination found she had suffered “multiple and extensive injuries” over a “sustained and extended” period of time.
A police spokesman in Jehlum, 108 miles north-west of Lahore, said the girl’s father and his wife were in hiding and 10 close relatives have been taken into custody for questioning and an investigation.
Among those detained include Mohammad Sharif, the father of Urfan Sharif, his brothers and cousins, the spokesman said.
Police in Pakistan often detain the close relatives of wanted suspects. However, they are not kept in jail to avoid the intervention of a court.
In a clip of the footage posted online by Sky, Batool shows no emotion as she describes Sara’s death as “an incident” and says that she and Sharif are willing to co-operate with UK authorities over the case.
Sharif and Batool left Britain with five children aged between one and 13, and Surrey Police want to question them over Sara’s death.
Sara’s mother Olga Sharif gave an interview to the Polish television programme Uwaga! in which she spoke of the harrowing experience of going to view her daughter’s body.
She said: “One of her cheeks was swollen and the other side was bruised.
“Even now, when I close my eyes I can see what my baby looked like.”
Ms Sharif separated from her husband in 2015 and Sara and her older brother had been living with her until 2019, when the family court ruled they should live with their father.
Ms Sharif still had equal rights to see the children and said while that was easy to maintain initially, it became increasingly harder over time.
Sara’s grandfather has told the BBC the girl’s death was an “accident” and three family members who left the UK for Pakistan will “ultimately” return to face police questioning.
Muhammad Sharif said he saw Sara’s father soon after he arrived in the city of Jhelum, in the South Asian country, and said his son had fled the UK out of “fear”.
Surrey Police are appealing for information to help them gain a picture of Sara’s life.