IT was Bridlington’s biggest unsolved mystery in recent times - and still is.
Despite a massive missing person search, which was to turn into a murder inquiry, the question then, as now, is where is Sybil Appelquist?
The 41-year-old apparently vanished off the face of the earth leaving all her possessions and her 49-year-old husband of one year John Appelquist.
Ten years ago this year month was the last time anyone in her family had any contact with her.
In November 2002 she was officially a missing person and in June 2003 her husband John was charged with her murder between December 2001 and November 2002.
Maintaining his innocence throughout he was said to have told police Sybil had driven him to work one day, left their Ford Fiesta car in Tesco car park off Hilderthorpe Road, and vanished without taking any of her possessions.
On the seventh day of his Hull Crown Court trial in February 2004 the judge stopped the case, believing the prosecution case was not sound and there was insufficient evidence to prove John Appelquist was guilty of her murder.
He instructed the jury to return a not guilty verdict and he was aquitted before any of the defence case was heard. John Appelquist never took the stand. The judge, Justice Andrew Smith, did say the police had proved beyond reasonable doubt that Sybil was no longer alive.
Sybil’s body has never been found.
Alan Brook looks back at the police investigation with Detective Inspector Anthony Cockerill who was on the original investigation team and talks to her friend and sister-in law Pam Appelquist and her brother, Anthony.
They have no doubt whatsoever she is dead but still have no answer to the same question, where is Sybil?