Police want to speak to any of the people pictured about the attack.

Police want to speak to any of the people pictured about the attack. Photo: Supplied

Detectives have released a picture of people they believe could help solve an indecent assault case, when a young girl was attacked during an Easter egg hunt near Phillip Island.

The girl was assaulted by an elderly man, about 75 years old, who had joined her group part way through the Easter fun day at Churchill Island on Easter Sunday, police say.

Morwell Sexual Offences and Child Abuse Investigation Team detectives believe four people captured in a closed circuit television image may be able to help them with the investigation.

It is believed a witness approached the group and confronted the elderly man, before telling other adults who were present what had happened.

Police previously described the man as having grey, thinning hair with a long comb-over and being of northern European appearance.

Anybody who can identify this group or beleives they have information that could assist the investigation is urged to phone Crime Stoppers on 1800 333 000.