TV presenter Anita Rani has admitted that discovering how her family suffered during the brutality of the partition of India for a BBC documentary has "changed" her.

In an episode of Who Do You Think You Are?, she travelled to the country to find out what happened to her maternal grandfather's first wife following the independence of India and Pakistan in 1947.

Rani, who is currently competing in Strictly Come Dancing, was left stunned when she discovered the horrific violence, including rape, murder and "sacrifice" that women were subjected to during the violent clashes.

After using historical records to trace her grandfather Sant Singh's background, she discovered his first wife Pritam Kaur had most likely been among the women who killed themselves to avoid being raped when their village in Western Punjab came under attack in 1947.

Their young daughter is believed to have died with her mother while Mr Singh was away serving with the Anglo-Indian army. His parents also died in the brutal months that followed independence.

A survivor from the village, 84-year-old Bier Hador Singh, recounted the harrowing details for the presenter: "My father was head of the village ... we began to feel the heat of the houses catching fire.

"We were all gathered together and my father had a large sword. The Muslims were demanding a girl. They said 'give us a young and beautiful girl and we will let you alone, let you get on with your lives'.

"Our father rejected their demand and said 'No, we won't give you our girls to save ourselves. Rather than let our girls succumb to this shame, we will kill them ourselves and hope they forgive us'."

Rani, who described herself as "not a traditional Indian girl", was reduced to tears as she heard how wives and daughters were beheaded by their husbands and fathers, while other women threw themselves down wells to escape "shame".

She said: "So your father took the decision that him and a couple of other men of the village would murder their own wives and daughters?

"It's so cruel. The rest of the women who were left, they made the decision that they would jump in the village well.

"It's the most shocking, horrifying account of what humans are capable of.

"I feel really angry. I hate that the world was in such a way that that was the only choice that women had. That men would decide their fate."

After speaking to Indian author Ritu Menon, who has documented women's experiences during partition, and learning how hundreds of thousands of Muslim, Sikh and Hindu women would have suffered a similar fate, Rani said her "blood was boiling".

"It makes me think if you were a cow at this time you had more chance of survival," she said.

"I don't know what I'm going to do but it's changed me.

"This moment has changed who I am."