Entertainment One has released a UK teaser trailer for Diana, the Oliver Hirschbiegel-directed drama about a secret affair that Princess Diana had shortly before her tragic death. Naomi Watts stars in the pic with Naveen Andrews as Dr. Hasnat Khan, the Pakistani heart surgeon Diana dated before meeting Dodi Fayed. Stephen Jeffreys wrote the script. The film was a hot property in Cannes last month where eOne made the acquisition for the U.S., the UK, Canada and Spain. The film goes out in the UK on September 20.