The restaurant floor has been closed for more than three years after a legal battle over safety concerns and rundown services ended with a confidential settlement, and with Alto Restaurant closing in February 2013.

It came after the restaurant's owner commissioned a building report that found outdated services posed serious health risks, the revolving floor controls were unsafe and the airconditioning and sewerage pipes were in poor condition.

A paper trail shows the building manager was also concerned about the elevator report and that action had been taken on only one recommendation of a 2003 fire engineering analysis and risk assessment by Warrington Fire Research.

Raine and Horne, which manages the building, would not say this week whether those concerns remained.

The tower's owner, Telstra, said it was considering a range of uses for the site, but did not detail them.

It said it had invested millions into refurbishing the building in recent years, but a major lift upgrade remains unfinished after a 2008 report said needed to be done by 2013.

It's expected to be completed in mid-2018, and work began in September 2015.

Telstra also did not confirm whether it had addressed all safety concerns raised in the report, but a spokesperson said the site complied with all safety requirements and building facilities, including the conferencing room, had been upgraded.

"Telstra has invested over $5 million at this site over the past two years in a range of building services, including electrical services, airconditioning and building degradation works."

The 195-metre tower opened in 1980 as the transmitting station for Canberra television and FM broadcasting services, and as a base station for other radio communication.

It remains crucial to the city's telecommunications.

It is also an iconic part of the Canberra vista rising above Black Mountain and has a history as a tourist site, though Telstra did not provide details of recent visitor numbers.

When asked if it was considering selling the tower or closing it to the public, as it contemplated in 2012, a Telstra spokesman said it had no plans to sell the site.

"Telstra Tower is an iconic destination for the local community and thousands of visitors to Canberra each year and it also supports critical broadcast and telecommunications infrastructure for providers servicing the Canberra region," the spokesman said.

Telecommunications infrastructure expert Anthony Goonan, who used to work for Telstra, said there was a common misconception that the tower was not needed because of the uptake of wireless technology.

"It provides a platform for mobile transmission and also provides coverage for all of Canberra's TV transmissions," he said.

"If the tower was not there it would not have as great effect on mobile transmitters and internet coverage because there are lots of towers around Canberra that do that, but if it did not exist you would have to build an alternate transmission point for Canberra's TV stations."

Adjunct professor in architecture at the University of Canberra Annabelle Pegrum believes the tower has significant cultural value.

She dubbed Sex Party candidates' recent comments that it is "ugly", an "awful eyesore" and "complete embarrassment" as "political attention seeking at its most nonsensical level".

"I'm aware of its condition internally and I think it's very sad," she said.

"But I think with some tender love and care it will be a must-see destination certainly as it was in the early 1990s, which has been lost somewhat."

While its proposal was initially controversial, and the building is not heritage listed, Ms Pegrum believed many had come to see it as a "welcoming landmark and beautiful statement", which added more to Canberra's landscape than it detracted.