Mandurah Detectives are calling on the public for help as they look to track down a male suspect as part of their investigations into an indecent act that occurred on the 558 bus from Secret Harbour on Wednesday, July 29.
Police are calling for information from anyone who may have been on the bus when the incident took place between 9.30-10.30am.
The suspect has been described as aged between 20 to 30 years, olive skin, unshaven with bad teeth.
He was wearing grey sweatpants and a grey top.
Anyone with information is urged to contact Crimestoppers on 1800 333 000 or Mandurah Detectives on 9531 8888, quoting reference IR 300720 1710 11972.