Juanita Joan Nielsen (née Smith; 22 April 1937 – disappeared 4 July 1975) was an Australian newspaper founder and owner, publisher, journalist, model, urban conservationist, and heiress.

Nielsen opposed urban development on Victoria Street, Kings Cross, Sydney, initiated by property developer Frank Theeman of Victoria Point Pty Ltd.[2] It is generally believed that she was killed because of her conservationism, and there have been strong suspicions of involvement of organised crime and police corruption.

In the early 1980s, two men associated with Kings Cross crime boss Abe Saffron were jailed for conspiracy to kidnap Nielsen based on incidents leading up to her disappearance.

[1] Prior to her publishing career Juanita worked at Mark Foy's as a glove model from 1953 until she travelled overseas in 1959.

[1] In 1962, she married a Danish merchant seaman Jorgen Fritz Nielsen in Kobe, Japan, but the marriage ended in divorce in 1967.

[1] Nielsen returned to Sydney in 1965 after living abroad and ran a fashion boutique at Mark Foy's for about five years.

[5] The Kings Cross community campaigned against the development, and successfully lobbied the Builders Labourers' Federation (BLF) to impose a green ban on the site in 1972.

[7] As a member of the Victoria Street Ratepayers Association, Nielsen also lodged an objection to the development proposal with the local council.

[7] BLF leader and prominent Communist Party figure Jack Mundey described Nielsen as an "upper class" person who was initially disapproving of unionism, communism, and squatting, but became more sympathetic.

Krahe was reputed to be involved in organised crime and he was suspected of murdering prostitute Shirley Brifman after she had accused him of corruption.

In 1973, when merchant seaman, jazz musician, and Communist activist Jack Rabald Fowler, commonly known as "Mick",[1] returned from a period working at sea, he found his rented house boarded up.

[17] The Carousel Club in Kings Cross (called "Les Girls" at other times)[20] was one of a number of bars and nightclubs controlled by Abe Saffron, who was a major figure in Sydney organised crime.

[23] On 30 June, Edward Frederick "Eddie" Trigg and Shayne Martin-Simmonds, both employees at The Carousel, went to Nielsen's house ostensibly to discuss advertising in NOW.

The two men played out their cover story, but Nielsen was listening in an adjoining room and after they left complimented Farrell on his handling of the query, teasing him by saying she might send him out on the road to sell advertising in NOW.

[25] On Friday, 4 July 1975, Nielsen went to the Carousel Club in Kings Cross for a meeting with Trigg about advertising as had been arranged the previous night.

[29] When Trigg was questioned by police he confirmed the meeting and produced a receipt Nielsen had given him for an advance payment on the advertising.

[32] In late 1977, Trigg, Shayne Martin-Simmonds, and Lloyd Marshall, all one-time employees of the Carousel Club, were charged with conspiring to kidnap Nielsen over the incidents prior to her disappearance.

[33] When interviewed by police on 6 November 1977, Martin-Simmonds confirmed that the advertising story was a ruse and that their actual intention was to kidnap Nielsen if she was alone and take her to see "people who wanted to talk to her".

He said that he and Trigg intended to: Martin-Simmonds told police he didn't know the identity of the people who wanted to talk to Nielsen.

The jury found there was "evidence to show that the police inquiries were inhibited by an atmosphere of corruption, real or imagined, that existed at the time".

[1][39] In 1994 the Commonwealth Parliamentary Joint Committee on the National Crime Authority criticised police failings and linked the Nielsen disappearance to property developers and the King Cross criminal underworld.

[1] The committee questioned the National Crime Authority's use of Jim Anderson as a protected informer as he was a suspect in the disappearance and other criminal activity.

A piece of paper in his pocket, supposedly a receipt signed by Nielsen for advertising money paid by Trigg, also had blood on it.

Her then boyfriend John Glebe gave evidence that Nielsen had told him about receiving telephone threats and he also testified that she carried cassette tapes in her handbag.

It didn't put us off, but you did look under the car for about two days afterwards because you thought, hang on a minute, what's all this about... And the nexus between government and big business and crime.