The 22-year-old woman died in King’s College Hospital on August 28 after being taken ill at a house in Knight’s Hill, Lambeth. Her family has been informed and a post mortem examination will be carried out on Monday.

One of her friends, a man in his 20s, was also taken to hospital in a critical condition and has since been discharged.

They are both believed to have taken ecstasy with other friends at Crystals nightclub in Lewisham, police said.

Analysis of pills seized from the address in Knight’s Hill found that they contained MDMA (ecstasy) and ketamine, according to officers.