Officers working for Waltham Forest's Gangs Task Force have arrested four people on suspicion of dealing drugs.
The intelligence-led operation was carried out on Tuesday at around 8:30pm at a house in Brunel Road, Walthamstow.
During the search of the property, officers found approximately 30 wraps of a powdered substance, believed to be class A drugs.
The seized drugs are currently being tested so the substance is unconfirmed.
A 45-year-old woman from Walthamstow, a 38-year-old from Leyton, a 24-year-old man from south west London and 23-year-old man from Walthamstow were arrested on suspicion of possession with intent to supply class A drugs.
All four have been bailed to October 2014 pending further enquiries.