Police are searching for a fourth man believed to be involved in an alleged assault of two teenage girls at Pyrmont.

Footage captured an attack at Pirrama Park where two 16-year-old girls were allegedly assaulted in March.

Three men – aged 23, 29 and 21 – were arrested shortly after and charged with affray and common assault.

The fourth man is described as being of Caucasian appearance, aged in his 20s, and was wearing a grey hoodie, dark pants and blue sneakers.