I thought I'd post this website here. Police are generally regarded as credible witnesses, and this is an Australian Police site encouraging officers to publish reports of sightings.
Officer Witness - Are you an officer with a UFO experience? Reports to PoliceUFO.com can be made with the guarantee of anonymity for the officer.
Tip Off - Do you have information about another officer, police-related UFO information, or news. We'd love to hear from you. Just provide as much infomation as you can.
Fill out and submit the following form or make contact at report@policeUFO.com
providing the following information...
There are downloadable Summary Reports for each calendar year, also various documents. Quite a good reference site with a careful, open-minded approach to it.
One thing caught my attention, though. On the Downloads
page there is an article titled