Natalie Wood's sister is demanding her former brother-in-law Robert Wagner clears up a series of unanswered questions about the actress' 1981 death as police detectives re-open their investigation into the tragedy. 

Lana Wood has been campaigning for answers for years and now she hopes actor Wagner finally opens up about what really happened the night her sister drowned off the coast of California.

Wood was believed to have died after falling overboard as her husband and their friend Christopher Walken had fallen asleep following a Thanksgiving party aboard Wagner's yacht The Splendour - but Lana insists she was far from happy with the conclusion of the case. 

And she's particularly bothered by Wagner's original testimony that suggested he thought Wood was "screwing around" on another boat, because "that's the kind of woman she is."