Lunar House was closed off to the public early this afternoon after a suspicious package was discovered by a member of staff.
The building was cordonned off and staff confined to their offices as emergency services and police flocked to the scene to investigate.
The package was found to be harmless.
A police spokeswoman said: “We can confirm that at 12.16pm today we received a report of a suspicious package at Lunar House, found by staff there.
“An appropriate police response was made.
“The package was determined to be non-suspicious.”
A spokesman from the London Ambulance service said: "We were called just after 12.40pm to reports of an incident at Wellesley Road.
"We sent one single responder, one ambulance, the duty officer and the hazardous area response team.
"Our staff did not treat any patients and the incident was stood down at 1.40pm."
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