Listed Singaporean developer Chip Eng Seng told the Singaporean stock market on Friday that it had sold the site for $A65 million, to an undisclosed buyer.

The firm bought the 3000-square-metre property for $35 million in 2013, but received planning approval for 1000 apartments from Mr Guy, who is now opposition leader, only in September.

Lord Mayor Robert Doyle and Melbourne City Council opposed the project, because it was so high it would overshadow the State Library forecourt, and would create wind and traffic issues, among other problems.

The purchase comes despite repeated warnings from the Reserve Bank of Australia that there is an oversupply of apartments being built, in Melbourne especially.

Designed by architects Elenberg Fraser, the apartment tower seen by Melbourne City Council in August would have virtually eliminated all direct sun on the State Library forecourt in mid-winter for a period from 2pm.

The site is bounded by a heritage-listed bluestone wall on the CUB site, that must be retained as part of the development.

Chip Eng Seng is yet to reveal the buyer of the site, and the Far East Consortium, spruiked by one industry figure as the purchaser of the site, dismissed this as a rumour.

CBRE agent Mark Wizel, who has sold many of the city's top sites, said that warnings of an oversupply in Melbourne's apartment market should not be taken seriously.

"The statistics simply don't lie - if we have more Asian migrants coming to Victoria than British, and if those Asian migrants prefer to live close to the CBD in an apartment, then surely this must impact the way in which the industry's researchers benchmark this cycle of supply versus [previous] cycles," he said.

"The sooner we start to realise that Melbourne as a city is being seen as a true International city in terms of our appeal as an investment destination the better. We must welcome and nourish Asian Capital, not resent it."