Artists Egon Schiele and Gustav Klimt can still stir up controversy

As if they weren't enough trouble while they were alive, long-dead expressionist artists Egon Schiele and his mentor Gustav Klimt were recently stirring up trouble on London's underground.

Huge posters depicting the Viennese artists' startling nude portraits were posted throughout London's underground and in German bus shelters.

Commissioned by the Viennese Tourist Board, the posters were to mark the 100th anniversary of the artists' deaths. But even now, in 2018, the images have been deemed too racy for public spaces.

Long thought of as protagonists in exploring human sexuality in Vienna, Schiele and Klimt frequently challenged conventional ideas about art with their paintings of women during the ''wild'' Secession at the turnaround of the 20th century, we learned on a guided tour of Vienna's Leopold Museum, which is holding a special exhibition of Schiele's work through to November this year.

Things took a very serious turn for Schiele and his muse, a former prostitute, when they made the rather risky decision to leave Vienna and seek inspiration in the small Austrian town of Neulengbach.

Their studio was often frequented by young delinquent teens – mostly girls – who would pose for the avant garde artist. He also found he could make a schilling or two on the side drawing pictures for those not necessarily interested in fine arts.

The enraged father of a 12-year-old girl set alarm bells clanging. Schiele had gone one troubled teen too far and police were sent to investigate his home. They confiscated more than a hundred pictures, including one drawing found pinned to a wall that was considered obscene, and in full view of the visiting teens.

In 1912, the artist was subsequently arrested on charges of pornography. Fortunately for Schiele, police got bored with the case and he only spent a month in jail on the grounds of "public immorality" – drawn from the one painting he'd left pinned to a wall authorities deemed to be on public display.

Schiele was rumoured to have purged his collection of young subjects following his jail time, as most have vanished into thin air. He set about improving his public image, ditching his lover, and marrying a more respectable Edith Harms in 1915. His female subjects seemingly evolved into adult women, replacing his predilection towards gawky teens.