Drugs raids have taken place around Merton this week as police crack down on alleged criminals ahead of Notting Hill Carnival.
Officers raided 11 addresses on Tuesday to tackle drugs and drugs supply around the borough.
Morden officers made one arrest for possession of class B drugs and arrested another person for suspected drugs cultivation.
Wimbledon police arrested one person on suspicion of supplying drugs and found a stolen phone at another address.
The arrests formed part of an operation targeting suspected criminals ahead of the carnival's 50th anniversary this weekend.
In total nearly 150 people were arrested across London on Tuesday. Police also seized £78,000 in cash.
Many of those arrested and bailed pending further enquiries will have bail conditions imposed on them, banning them from attending the carnival.
Chief Superintendent Robyn Williams, MPS spokesman for Notting Hill Carnival, said: "We are committed to ensuring that Notting Hill Carnival remains a safe, vibrant and enjoyable event.
“Today's operation was aimed at ensuring that those who set out with the intention of causing trouble at carnival will not succeed."
If you have any information that could help police, call Crimestoppers anonymously on 0800 555 111.