Fairfax Media has received photos of the debris found near Augusta which investigators have since confirmed is not linked to the missing Malaysian Airlines flight MH370.
Mat Franklin and his son discovered the debris on Easter Monday four kilometres from Augusta.
Mr Franklin went to work on Tuesday before trying to report his findings.
"It looked pretty distinctly like a piece of aircraft. I didn't want to raise any alarms, I just wanted to get an opinion," he said.
Mr Franklin decided to get advice from the Busselton Aero Club on Wednesday who then passed it on the Busselton police.
Senior Sergeant Steve Principe said the Busselton station received the object between 2.30 and 3pm on Wednesday afternoon.
It was from there that the possible link to the MH370 arose.
Information was then passed on to the Australian Transport Safety Bureau (ATSB) and the Joint Agency Coordination Centre (JACC) for further investigation.
The bureau announced on Thursday morning that there was no link to the missing MH370 aircraft but investigations were still ongoing.
"They've had the top forensics examining it and should have been able to tell what it is by now," Mr Franklin said.
"I still believe it is a piece of aircraft because they won't give it back to me."
Whilst the debris have been confirmed as unrelated to MH370, ocean experts say it is likely that debris from aircrafts could wash up on the WA coast if it's caught up in the Leeuwin Current.
This isn't the first time unusual objects have washed up on the shore at a beach at, or near, Augusta.
Last year the navy investigated after an object initially believed to be a bomb wasreported found at a beach in Augusta.
Augusta abalone diver Joel Veitch also came across a blue marlin approximately 2.5 metres long and weighing 250 kilograms dead in the water 100m south of the new marine wall in Augusta.
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