A reward of up to £20,000 is being offered for information leading to the arrest of the suspect in a chemical attack on a mother and her daughters in Clapham, police have said.
Abdul Shokoor Ezedi was last seen leaving Tower Hill Underground station on 31 January at 21:33 GMT, the Metropolitan Police said.
People who know where he is have yet to come forward, detectives said.
The injured woman, known to Ezedi, is critical but stable in hospital.
The attack – carried out with a corrosive substance – took place on Lessar Avenue, Clapham at 19:25 GMT on Wednesday.
The mother, 31, is said to have experienced life-changing injuries while her daughters, aged three and eight, suffered injuries not “as serious as first thought”.
The Met’s Cdr Jon Savell said a laboratory analysis of the substance from the attack site found it was a “very strong concentrated corrosive substance, either liquid sodium hydroxide or liquid sodium carbonate”.
“Further enquiries are ongoing including comparison with the containers seized from Ezedi’s address in Newcastle,” he added.
Dozens of calls have been received by the Met following an appeal, and searches have taken place at two addresses in east London and three in Newcastle.