Police are appealing for witnesses after the man was discovered with multiple injuries at a flat in Bartholomew Square.
Officers were alerted to the incident about 11.30am on Saturday 7 August, a police spokesman said. The victim – a 37-year-old man from London – was taken to hospital for treatment, where he remains in a critical but stable condition.
The spokesman added: “The scene has been secured for forensics examinations.
“Anyone with any information about the incident is asked to report it online or call 101, quoting Operation Lasso.”