Alexander Skarsgard on board 'Passing'

Alexander Skarsgard has joined Ruth Negga and Tessa Thompson-starrer "Passing".

According to Variety, the details on the "Big Little Lies" star's character are unknown.

The film marks the directorial debut of actor Rebecca Hall who is directing from a script she adapted from Nella Larsen's Harlem Renaissance novella of the same name.

"Passing" follows the unexpected reunion of two high school friends, whose renewed acquaintance ignites a mutual obsession that threatens both of their carefully constructed realities.

Larsen's story was first published in 1929 by Knopf and her exploration of race was informed by her own mixed racial heritage and the increasingly common practice of racial passing in the 1920s.

Also starring Andre Holland, the shoot of the film is underway in New York.