Police are investigating a brazen daylight assault and robbery in the Perth CBD earlier this month where a group of three young men stole a man's recently purchased Christmas presents.

Police are seeking witnesses to the assault and robbery, Credit:Marina Neil ZZN

On the afternoon of December 17 a man in his 20s was crossing Wellington Street near Yagan Square and the Horseshoe Bridge when he was approached by three young males.

The group pushed the man to the ground and assaulted him in front of onlookers.

While he was laying on the ground the group grabbed his wallet and some recently purchased Christmas presents before running away.