It comes after the BBC said it has seen the letter from Shamsa's younger sister Princess Latifa, calling for the police to re-investigate the case from 20 years ago.

The force said: "We can confirm officers have recently received a letter, dated February 2018, in relation to this case which will be looked at as part of the ongoing review.

"In addition to this we are also looking at the contents of the recent Panorama documentary to identify whether it includes anything of significance to our case."