News from the American Film Market (AFM) confirms that the inevitable Princess Diana biopic is finally on its way, and current star of the moment, Jessica Chastain will play the iconic figure for director Oliver Hirschbiegel (Downfall).

This won’t be a straight take on the Princess’s however, and will concentrate on her secret affair with heart surgeon, Dr. Hasnat Kahn, which lasted for two years around the mid-nineties. It was a relationship which meant a lot to Diana, so much as that it’s rumoured she considered converting to Islam so they could be together legitimately.

While this is yet another British iconic to be played by an actress from the US (Meryl Streep’s portrayal of Margaret Thatcher will be released on cinema next January) Chastain certainly looks the part, and this two-hander (from The Libertine scribe Steven Jeffreys) could potentially offer a nice alternative to the usual multi-character, lifetime-spanning biopics out there. Pre-production is set to begin in March 2012.

Via Collider.