Detectives are releasing images of a man they want to speak to following a series of fires.
Police and London Fire Brigade received calls to a fire in a field off Woodmansterne Road at the junction with Lacrosse Way, Merton at around 12.30pm on June 26.
The fire was put out, and caused damage to a number of properties.
Some houses were evacuated as a precaution.
The incident has been linked to a subsequent fire at the same location on July 19.
There were no reports of any serious injuries. There have been no arrests at this time. The fires are believed to have been caused deliberately.
Police had also received reports of a man with a knife seen acting suspiciously in the area.
Anyone who has information that could help police should call 101 ref CAD 3210/26 Jun. Alternatively tweet @MetCC or, to remain 100% anonymous contact Crimestoppers on 0800 555 111.
Pictured top. Police would like to speak to this man. Picture: The Met