Police were called to reports of an assault at a property in Portland Place at 7am on February 23.
Officers and paramedics attended and four men were taken to hospital, three with stab wounds.
Their injuries were assessed as non-life threatening.
Three men were also arrested, one man on suspicion of GBH and possession with intent to supply, one man on suspicion of GBH and another man on suspicion of possession with intent to supply.
A Section 76 Closure Notice has been placed on the property to prevent further disruption to the local area.
A spokesperson for Metropolitan Police said: “Police were called to an address at Portland Place, W1 at 7am on Sunday, 23 February following reports of an assault.
“Officers attended with the London Ambulance Service and four men were taken to hospital.
“Three of the victims had sustained stab wounds. Their injuries are not believed to be life-threatening.
“Police arrested three men, including one man on suspicion of GBH and possession with intent to supply, one man on suspicion of GBH and another man on suspicion of possession with intent to supply.
“A Section 76 Closure Notice has been placed on the property to prevent further disruption to the local area.”
