Two men have been arrested on suspicion of criminal damage following an incident at the Stephen Lawrence memorial plaque.
The Metropolitan Police said the incident at the plaque on Well Hall Road, south east London, happened at around 12:40am yesterday.
The men, aged 18 and 19, were taken into custody and have been bailed until May 29.
A public inquiry is to be launched into the work of undercover officers
It is believed that a flowerpot containing flowers was broken and that the plaque was spat at.
Officers from Greenwich borough are investigating, police said.
Lawrence died after he was stabbed to death aged 18, after being set upon by a gang of white youths while waiting at a bus stop in south London in 1993.