Police investigate a flat in Constable St, Newtown, where the body of a woman in her 30s was found on Tuesday night.

A call to police by concerned friends led to the discovery of a body in a Wellington flat.

A woman in her 30s was found dead by police in her Constable St home in Newtown on Tuesday night, after worried friends contacted them concerned about her whereabouts.

Detective Senior Sergeant Warwick McKee said officers knocked on the door of the woman's flat in the Wellington suburb Newtown on Tuesday night with no answer.

ROSS GIBLIN/ FAIRFAX NZ The scaffolding at the rear of the building, which police climbed to get into the flat after receiving no reply.

They then climbed up on scaffolding behind the back of the flats, and were able to see into the flat, where the woman lay dead.

Police are still investigating how she died, and would not comment on whether her death was suspicious, or whether her body showed any signs of injury.

They still had to remove the body from the flat and conduct a post-mortem.

ROSS GIBLIN/ FAIRFAX NZ Police staff in hooded white protective suits and breathing masks entered the flat on Wednesday afternoon.

About 1pm on Wednesday, police staff in hooded white protective suits and breathing masks ducked behind police tape at the nine-flat property to photograph the woman's flat.

Inside, the curtains were tightly drawn.

Police have so far described the death as "unexplained".

MICHAEL FORBES/ FAIRFAX NZ The scene in Constable St on Tuesday night after the body was found.

They were still talking with neighbours and friends to try and establish where she was last seen.

"Police will be in the neighbourhood speaking to the community and residents to determine her recent movements in and around the address," McKee said.

Arrangements were being to contact her next of kin.

A next-door neighbour said the woman had not lived in the flat long.

She said she hadn't heard anything from the flat, just a wall away from her own, since she moved in.

"The police came around about 5.30pm looking for a girl missing. Suddenly there were lots of police cars."

Another neighbour, Isaako Schuster, said he saw the woman last week.

"She opened the window and called out to me about some work I was doing, then went inside her room. That was the only time I ever saw her."

Next door, Chuni Dahya said it was strange to know a dead body was lying in the flat.

"It's a weird feeling. Nothing happens in this neighbourhood, and we've lived here 60 years."

Neighbour Laura Gardner said she saw three police cars and a fire engine arrive outside the house about 9pm Tuesday.

One person inspecting the scene appeared to be wearing a hazardous materials suit, she said.

"I was getting a bit edgy so I went over and asked a police officer what was going on, and he said there was nothing for me to worry about."

Constable St resident David MacKenzie said he was home at 6pm when the body was found, but did not notice any commotion until about 9pm when multiple police cars and a fire engine arrived.

"None of them had their sirens on. It was all very quiet," he said.