A police spokesperson said the case relates to a woman who was on a bus to New Brighton about 8.30pm on November 13, 2023.
"An unknown male was also on the bus who was being disruptive and inappropriate.
"The woman got off the bus at the same time as the man who then made extremely inappropriate comments to her, lunged at her and then a short time later exposed himself to her.
"Another member of the public witnessed this happening and kindly gave the victim a lift home.
"Unfortunately we have not been able to do this as of yet and are hoping someone will know who he is and report this to police."
Anyone with information should call the police on 105, quoting file number 231115/2332 or anonymously phone Crime Stoppers on 0800555 111.