Police have released further images of a man found collapsed in Camden in a bid to locate his family or friends.
The unknown man was found on the street outside University College Hospital after suffering a heart attack at around 4.30pm on Boxing Day.
He was not carrying any identification on him at the time.
The man - who is described as of light skinned black or of Asian origin - remains in an induced coma.
Police have now released a further image of him in his hospital bed to try to identify him.
An earlier image showed the man with cuts and grazes to his face.
Detective Constable Tom Boon, from the Central North Command Unit's Missing Person Unit, said: "It is almost a month since this man was found collapsed outside University College Hospital and we are still trying to trace his next of kin.
"We hope that by releasing this new photo, someone may recognise him and come forward."
Det Con Boon urged anyone with any informtion to contact police.