A group of about 40 Extinction Rebellion protesters camped outside the main entrance this morning, unfurling banners reading "BBC, your silence is deadly" and "stop funding climate change".
Several police vehicles have been reported at the scene whilst officers are patrolling the site.
A video by a woman on the scene showed a man being led away by police officers amidst clamour from the activists.
Financial journalist Paul Lewis tweeted: "Locked out of BBC by extinction rebellion."
Yesterday, the group continued their ongoing 'take-over' of the city as they disrupted flights at London's City Airport.