The developers who illegally demolished Carlton's Corkman Irish Pub doubled the value of their site overnight, property experts say.

The property where the pub once stood is now valued at between $8 million and $10 million, according to an analysis of nearby sales completed by property agents Savills Australia, after a request by Fairfax Media.

The demolished pub was built 159 years ago and stood at the corner of Leicester and Pelham streets.

Developers Stefce Kutlesovski and Raman Shaqiri paid $4.76 million for the pub last August. It was torn down by Shaq Demolition and Excavation, which is half owned by Mr Shaqiri, on October 15.