A murder investigation has begun following the discovery of a body in south west London.
Two women were apparently "taken against their will", by a man they knew, to an address in Kingston Upon Thames on Wednesday night, police said.
They were violently attacked, resulting in the death of one of the women. The other woman escaped and was treated for stab or slash wounds in hospital.
Two men have been arrested on suspicion of murder.
Officers visited the women's addresses in Sutton and Merton following a concerned call about their safety at about 17:00 BST on Wednesday.
They found no trace of either woman when they visited but were informed by a south London hospital at 19:18 that a woman in her 20s was being treated for stab or slash wounds.
Police went to a residential property in Coombe Lane West, Kingston Upon Thames, at about 20:00 where they discovered the body of the other woman, who was believed to be aged 19.
Her next of kin have been informed and post-mortem tests will be carried out in due course.
"Our investigation is at an early stage, and we are doing everything we can to fully understand the circumstances of this terrible attack on two young women," Det Ch Insp Samantha Price said.
"It is clear that both women were subject to a violent attack, resulting in the death of one woman.
"Fortunately one of the women managed to get away from the address and seek help, how this happened will form part of this investigation."
A 33-year-old man has been arrested in Kent on suspicion of murder. A 28-year-old man was stopped in New Malden, south west London, and is being held on suspicion of murder.
Police also arrested a 29-year-old woman on suspicion of assisting an offender and she was released on Thursday pending further enquiries.