Police have reprimanded an officer after he posted images associated with white supremacist groups to his personal social media account.

The same officer drew criticism for hand gestures he made during police clashes with protesters at the International Mining and Resources Conference in central Melbourne this week.

An image posted by the officer. Credit:Facebook

Victoria Police have confirmed the officer seen making a hand gesture – which they deny was used as a ‘white power’ symbol – has posted images to his social media account that are closely associated with the notorious 4chan online forum and alt-right community.

For the second time in 24 hours, Victoria Police have expressed their "extreme disappointment" at the behaviour of an officer involved in the operation.