The future of one of New Zealand's oldest prisons remains uncertain five years after it closed. Shane Cowlishaw and Lawrence Smith were granted access to the building known as The Rock, where they discovered old stone walls steeped in history and legend.

It's not even the pigeons writhing on the ground, shred to death by the razor wire high above.

The rats don't bother him, he has seen plenty of those before.

It is, cleaner Sahil Kumar says, a rather unsettling place to work.

It's the ghosts.

If you ask the people who continue to maintain The Rock since it closed for good in 2011, the old Mt Eden Prison is haunted.

There is a lone loudspeaker that continues to crackle and moan, despite the PA system being shut down five years ago.

An electrician was called in to investigate. He cut all the wires leading to it, but the disturbing sounds still echo through the empty hallways.

It's unsettling. But another of Kumar's stories is even more so.

Crouched down in a cell hard at work, a contractor brought in for emergency repairs swears a Maori inmate appeared behind him and yelled, "get the f... out".

By the time the contractor scrambled to his feet, the man had disappeared.

The contractor sprinted out of the prison, and refused to return.

Just the other day, Kumar says, a colleague needed to head in to the old prison at night to check on something.

"I've never seen anyone so loaded down with torches, he was shining like a lighthouse."