SYDNEY’S busiest court complex, the Downing Centre, went into lockdown yesterday as a man burst into the building and ordered people to “get on the ground”.

The man had earlier been carrying a machete when he was allegedly involved in an altercation in nearby Hyde Park.

Witnesses said the man left the machete on the ground outside the Liverpool St court complex before he went inside about 10am and began yelling at people to “get down”.

media_camera The Daily Telegraph understands armed police were in the complex at the time and stopped the man, who is now in custody / Picture: Ross Schultz

Armed police were already inside the court complex and quickly arrested the man, who was last night undergoing a mental health assessment.

A police spokeswoman yesterday said sheriff’s officers, who are responsible for court security, had called for back-up when the man, 20, began yelling and ordering people to the ground.

The doors were locked but the building — which is the city’s busiest court complex, housing local and district courts and which backs on to John Maddison Tower where the Lindt Cafe siege inquest is being heard — was not evacuated because the situation was quickly brought under control. The doors were reopened and hearings resumed as normal by 11am.

The police spokeswoman said the man was not armed when he entered the building and was quickly stopped and arrested by police officers. She said police would review the mental health assessment before considering laying charges.