Course it's an open secret, that's why under sharia law it's called an honour killing and not murder.
'Crimes' include not wanting an arranged marriage, seeing somebody of another race/religion, insuffient dowry, or simply a groom not liking the look of his new bride. My mother told me that she once washed a woman who'd been thrown from a speeding car because she'd given birth to a baby girl and not the boy her husband wanted.
Back in the 1970's you should have seen the burns unit at the women's hospital. At any given time over half of it was women of Indian/Pakistani origin, All used to tell the same story, the little cookers they used that used to run on calor gas or paraffin had just 'blown up'. Nine times out of ten the marriges had been arranged, often the women being bought straight from India/Pakistan with no family and no english.