A police dog found 60 wraps of cocaine, eight blocks of cannabis resin and six more wraps of herbal cannabis after officers visited a house in Teddington.
The officers were visiting the house on an unrelated matter but arrived to find cocaine and rolled-up bank notes in the kitchen.
The police arrested a man in his late-20s and a woman in her 30s after the more drugs were found by the dog around the house.
Upon returning to the house they seized £4,000, more drugs, knives, a BB gun, expensive clothes and computer games.
Richmond Police tweeted: “60 wraps of cocaine, 8 blocks of cannabis resin, 6 wraps of herbal cannabis. Thanks to @MetTaskforce #dog unit for help with drugs search!”