The police found empty containers with corrosive warning labels on them while searching an address in the hunt for a man wanted over a chemical attack in Clapham.
Footage shows officers entering the address in Newcastle - one of three that have been inspected in the city, on top of two in east London.
Forensic tests are currently ongoing to see if the containers held the substance used in the attack.
The nationwide manhunt for suspect Abdul Ezedi has entered its third day as police urged the seriously injured man to "do the right thing" and hand himself in.
Afghan-born Ezedi, who lived in Newcastle, was described by police as having "significant injuries to the right side of his face".
Dozens of reported sightings put him in Croydon and Streatham as well as on a Victoria line Tube train after Wednesday night's "targeted" attack on a woman and her two daughters with an alkaline substance in Clapham.
The 31-year-old woman hit by the corrosive liquid has "life-changing" injuries and was "very poorly" last night. Injuries suffered by the girls, aged three and eight, are not as severe as was first feared.
Mr Ezedi's relative told Sky News on Saturday that they were "worried" for his welfare and wanted to know if he was "alive or dead". They also alleged that he was in a relationship with the female victim.
It comes after detectives found two empty containers with corrosive warnings on the label following raids on an address in Newcastle.
