John Patrick White, who lives in Islington, was last seen on August 13 when he withdrew some money from a post office in Newington Green.
Concerned relatives have not heard from the 61-year-old, which they say is out of character.
John’s brother William is pleading with him to make contact.
He said in a statement: “John, we are all worried and concerned about you. Whatever the issues that are troubling you, we love you, we want to help and we can help. Please make contact with one of us or the police.”
John’s family discovered he was missing and alerted police shortly before midnight on Monday, August 14.
An immediate investigation was launched by officers making enquiries across the UK, including enquiries in John’s birthplace in Ireland.
John arrived in the UK from Ireland in 1981 and has spent the majority of his time living in the areas of Holloway and Islington.
Enquiries established that John had left home between 9pm on August 13 and 10pm on August 14.
Met officers know he withdrew cash from an ATM at a post office in Newington Green on the Sunday evening (August 13) – and that is the last reported sighting anyone has of him.
John is described as approximately 5ft 8ins tall, of stocky build, with grey shaved hair and blue eyes.
When he was last seen he was wearing a yellow T-shirt and blue jeans.
When he went missing, John had with him a blue bicycle, which is distinctive as it does not have any insignia and has been spray painted.
Det Insp Adam Langley, from the Central North BCU, is urging the public to help locate John.
He said: “Since John’s disappearance, we have completed extensive enquiries and searches in a bid to find him and we believe that he could be anywhere in the country.
“I am very keen to hear from anyone who knows John and who may have seen or heard from…
