A reward of up to £20,000 is on offer for information leading to the arrest of suspected Clapham chemical attacker Abdul Ezedi.
Investigators believe there are people who know where he is who have not come forward and they warned anyone found assisting him faces arrest.
They also released footage showing him in a Tesco on Caledonian Road in north London, filmed at around 8.45pm.
This would have been shortly after a 31-year-old woman and two children were attacked with a corrosive substance on Wednesday night, which Ezedi is suspected of carrying out.
In the update released on Sunday afternoon, the Metropolitan Police updated their most recent sighting of him, saying that the 35-year-old was seen at 9.33pm when he exited Tower Hill Underground station.
This suggested he continued his journey from the previous sighting point at King's Cross.
He had changed trains at Victoria, where he arrived on the Victoria line at 9.10pm and then departed on the eastbound District line at 9.16pm.
The police also added that the liquid used in the attack was a very strong concentrated corrosive substance, either liquid sodium hydroxide or liquid sodium carbonate.
Commander Jon Savell said: “I am hugely grateful to the public for the significant number of calls that we have received.
“Your help is critical. A reward of up to £20,000 is now available for information leading to his arrest.
“I must warn anyone who is helping Ezedi to evade capture - if you are harbouring or assisting him then you will be arrested."
The Met is working with the Home Office, UK Border Force, UK Visas and Immigration, the National Crime Agency, British Transport Police and several other police forces to track the man down.
Police have been raiding addresses in London and Ezedi's home in Newcastle following the incident in Clapham.
Their most recent update said the woman, known to Ezedi, was in a critical but stable condition in hospital but the children had not had life changing injuries.
Ezedi is a former Afghani national and is said to have been given British residency on account of converting to Christianity.
On Sunday, former home secretary Suella Braverman called out chruches for helping with the application process
Abdul Ezedi, from the charity the Afghanistan & Central Asian Association said: “Abdul, I am speaking directly to you.
“I want you to go straight to a police station immediately.
“You have a serious injury that needs to be seen to but, more importantly, you must do the right thing and hand yourself in to police.
“This has gone on for long enough. You can contact the charity if you wish and we can speak to you, and work together so that you can help the police with their enquiries.
“Abdul, please contact us as soon as you can, call 999, or go to a police station.”
Anyone with information about Abdul Ezedi is asked to call 020 7175 2784 or for an immediate sighting dial 999.
To remain anonymous, please contact the independent charity Crimestoppers.