Left: Otto Fenn, c.1952. Ink on white bond paper. Courtesy The Andy Warhol Foundation for the Visual Arts, New York.

Mark McLaughlin checked to see no-one was looking and sneaked into the private world of a superstar artist.

Edinburgh goes 'pop' this spring with a new exhibition of private drawings by Andy Warhol, at Inverleith House until May 25.

It is a collection of highly personal drawings from the artist's estate, done at the same time as his commercial work as an illustrator for advertisers and fashion magazines in the 1950s.

Pop-art has been viewed suspiciously in some artistic circles since its inception, and the work of the scene's most (in)famous icon is not short of detractors. This latest showcase isn't likely to win anyone over either, and Warhol fans expecting to see mass-produced Marilyns and Campbell's soup tins will also be disappointed.

Instead, we are treated to a series of briskly drawn caricatures of unknown male figures, thought to be friends from parties and homosexual get-togethers.

Right: Unidentified Male Portrait, c.1952. Ink on white bond paper. Courtesy of The Andy Warhol Foundation for the Visual Arts.

The very first picture in Room 1 introduces us to the recurring themes of the exhibition: androgyny, homosexuality and art produced in the heat of the moment.

It is a sketch of a male couple, cheek-to-cheek and holding hands. The side parting and strong dimpled chin of the man on the right strongly reflects Warhol's own distinctive features, and may be a crudely drawn portrait of himself and a partner.

The bottom of Warhol's mouth has been tip-exed out, indicative of the speed and lack of care applied to this and the rest of the drawings.

However, while this drawing suggests a monogamous and close relationship, albeit between two men, the rest are of a seedier nature.

As we delve deeper into Warhol's skewed mind he reveals a world in which androgyny is stripped away, along with inhibitions, to reveal definite homosexual intent.

At first glance the characters appear feminine, with long eyelashes, suggestive gazes, fur coats and glittering jewellery. However, in Room 2 the heads are turned to reveal distinctive Adam's apples, and the coats removed to show definitely masculine bodies

Left: Unidentified Male Portrait and Upper Torso, 1952. Ink on white bond paper. Courtesy of The Andy Warhol Foundation for the Visual Arts.

With the androgyny gone we dive deep into blatant homoeroticism. Room 3 shows a man, his bald head removing any uncertainty, gazing seductively at a string of pearls.

He looks on, eyes wide and with open mouth, wrapping the pearls around his left hand (replete with wedding ring) and putting them in his mouth.

An androgynous winged fairy looks on from the opposite wall, proudly displaying the pearls and perhaps indicating their significance as a masturbatory aid amongst homosexual men.

Maybe we are diving too deep into Warhol's pre-emancipated 50s underworld for comfort, and this exhibition will undoubtedly leave the morally narrow-minded with a bad taste in the mouth.

But remember these drawings were never meant for public display, and although overtly homoerotic they are never pornographic.

Andy Warhol: Private Drawings from the 1950s is an intriguing insight into the formative years of an artistic icon at a time of homosexual repression, and the pen-and-paper equivalent of a cheap-thrill.