A woman in her 20s is being held against her will by a man armed with a weapon at an address on Daysbrook Road, South West London
Armed officers were called just after 1.00pm on Wednesday to property in the road.
The incident remains ongoing with armed officers at the incident and a cordon in place.
UPDATE:10.30pm Met police say a man has been arrested at the scene.
The woman was not injured during the incident.
Both are said to know each other.