A man has been charged after allegedly smashing a NSW Parliament House window with a metal barbell in the early hours of this morning.

Police allege the 37-year-old caused the damage after entering the main forecourt on Sydney’s Macquarie Street about 2.40am. 

A crime scene was established and an investigation begun.

A NSW Parliament House window was smashed with a metal barbell early this morning.A NSW Parliament House window was smashed with a metal barbell early this morning. (Nine)

Over two hours later, police arrested the man about 40 kilometres away at a home on Oldfield Street in Greystanes.

He was taken to Granville Police Station, where he was charged with destroying or damaging property and entering inclosed land without a lawful excuse.

He was refused police bail and will face Parramatta Local Court today.

A traditional barbell weighs about 20kg. 

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