Three men aged 21, 21, and 45 initially arrested in connection with the incident have had their police bail cancelled and are no longer suspects.
An investigation was launched on November 2 after a reported assault in James Dunn Park, Walney, at 2am.
Detective Inspector David Stalker of Barrow CID said patrols had been stepped up on the island to reassure the public.
He added that there had not been any other similar incidents reported since or any males seen acting in a suspicious manner.
He said: “The three males initially arrested have been released and no further action will be taken in relation to events that night.
“It remains and open investigation and we will continue to investigate the circumstances of the incident.
“Post incident there has been a lot of police activity on Walney to provide reassurance to the community.
“These types of incidents can cause concern, but the area remains a safe place to live.
“Anyone with any information regarding the alleged incident on November 2 is asked to get in touch with police in Barrow.”
Anyone with any information should call 101 and ask for Barrow CID or call Crimestoppers anonymously on 0800 555 111.