Police are searching Cannon Hill Common as part of their search for Stuart Hazell.
Officers are at the scene along with a police sniffer dog unit.
A police helicopter has been seen flying overhead.
A police source said it is believed Mr Hazell was in the area earlier.
The common lies between Morden and Rayne's Park.
Police are looking for Mr Hazell as part a murder inquiry after a body was found at the home of Tia Sharp’s gran.
Tia disappeared last Friday and a major police operation was launched to find the missing schoolgirl.
The body found at the house has yet to be identified but police are searching for Hazell, the partner of Tia's grandmother Christine Sharp, to be interviewed in connection with the case.
Police have warned Mr Hazell, 37, should not be approached and if he is seen members of the public should call 999.
Police cordoned off the area around Christine Sharp’s home, 20 The Linden, this afternoon and said it was part of a pre-planned search.