IT'S the question the British public has been pondering for weeks.

Just who killed Lucy Beale on Eastenders?

Tonight the mystery will finally be solved - and if the bookies are to be believed a family member is the culprit.

Betfair currently have Lucy's 11-year-old brother Bobby and step-mum Jane as joint favourites at odds of 3-1.

Next up is dad Ian at 7-1 along with step-sister Cindy, while her twin brother Peter is next on the list at 8-1.

Outside of the family, Ben Mitchell is listed at 11-2 while a flood of bets have been laid on Abi Branning after her dad Max said he “knew she killed Lucy” in an episode earlier this week.

Rank outsiders include Dot Cotton at 80-1 and 'Dirty' Den Watts at 100-1.

Eastenders, which is celebrating its 30th anniversary today, is showing an hour-long live episode at 7.30pm on BBC1.