Police are hunting for a burglar who escaped from a prison van outside their Brixton station.
Kwami Richards escaped from the van, operated by a private security firm, at around 2pm on Friday as he was being transported back to jail.
The 42-year-old had been detained for breaching his licence conditions after serving a sentence for burglary.
He was pursued by a police officer into Brixton underground station.
The officer was assaulted as he attempted to detain Richards, who boarded a Victoria line train.
People are warned not to approach Richards, who has links to Wandsworth, and call 999 immediately if they see him.
A Metropolitan Police spokesman said the force was investigating how Richards managed to escape the van.