Metropolitan Police Marine Policing Unit
A planned Black Lives Matter rally has been cancelled amid fears of clashes between groups.
A pile of clothing was found on the bank of the bathing area.
A joint operation among several European countries has led to the arrest of almost 90 members of the 'Ndrangheta, the organised crime family based in Calabria, southern Italy.
"Knife crime and gang violence, I think it’s just a lifestyle now."
Police say there was a "possible disturbance" before the fall.
Police have conducted a search of an address in south London.
CS spray was also used.
The officer was pursuing a stolen bike when the incident took place.