His death was not being treated as suspicious and officers were in the process of notifying his next of kin.
The St Paul's apartments were built in 1999 and designed by renowned New Zealand architect Ian Athfield, who died in January last year.
The four-building complex was one of Wellington's largest leaky-building battle in 2012, with all 114 apartments suffering from leaks and damp.
The discovery is similar to an incident which occurred in 2013, when an 85-year-old man's body lay decomposing in his retirement village flat for two weeks before he was found.
Richard Giese, a former top musician who was principal flautist with the New Zealand Symphony Orchestra from 1962 to 1986, died of natural causes at his flat in Kilbirnie, Wellington.
He was only found when a neighbour, and fellow resident, queried why she hadn't heard his flute for several days and started making her own inquiries.
In September last year, a grieving woman was found to have bathed and cared for her husband's decomposing body for weeks in their Titahi Bay home.
The body was found after neighbours complained about the smell, but the woman, in her late 50s, would not admit the body was her husband's.
Police had to use dental records to identify the man as his body was so badly decomposed. It appeared the man died of natural causes.