Popular Perth amusement park Great Escape will be completely demolished as secretive new plans to "make use" of the site with an unnamed company move forward.

The Hillarys Boat Harbour attraction was closed indefinitely after months of speculation in September last year, and property management agency the Wyllie Group revealed it was "desperately seeking to fill [the] tenancy".

Whoever takes up the lease will be cashing in on a prime bit of real estate. Credit:6PR News

Despite calls from locals and business owners to revive the once-popular tourist attraction, 6PR's Simon Beaumont said a member of the public reported significant demolition works underway on Wednesday morning.

Speaking to WAtoday, a Wyllie Group spokesman confirmed the entire Great Escape amusement park would now be demolished to make way for a new development.