JEALOUS Nat Fraser was "stalking" his estranged wife because he didn't want her to see anyone else, a murder trial heard.
And when he was asked about a hammer lying in the Elgin home he once shared with wife Arlene, Fraser is supposed to have said: "If I was going to do it, I wouldn't use a hammer."
He also showed a great interest in a helicopter fitted with heat seeking equipment which police were using in their search, the High Court in Edinburgh heard.
Arlene's big sister, finance director Carol Gillies (49), from Renfrewshire recalled conversations from 14 years ago when she gave evidence on Friday.
Mrs Gillies said Arlene was a "brilliant" mum whose son and daughter always wore trendy clothes because Arlene herself was very trendy.
But the trial heard, Arlene was unhappy in her marriage and seeking a divorce. She and Fraser were living apart in April 1998.
Mrs Gillies said she was visiting her sister and Arlene borrowed her car to go shopping. As she left, Arlene warned Mrs Gillies that Fraser might turn up.
"Arlene said that she thought he was stalking her," Mrs Gillies told the trial. "As I recollect, I think he thought that she was seeing someone else and he didn't want her to have anyone else."
Mrs Gillies also described a conversation in the house in Smith Street, New Elgin, soon after Arlene vanished when she drew attention to a hammer lying on the floor.
On another occasion when talk turned to the helicopter: "He (Fraser) wanted to know more about the technicalities."
Mrs Gillies said the rest of the family, who had not yet given up hope, were thinking: "Oh no, they are looking for a body, you know, what does this mean?
She continued: "I have to admit my details are a bit sketchy on that but I do remember Nat sitting there and saying: 'Oh, how does that work?"
The trial also heard how Mrs Gillies thought the Smith Street house was unusually tidy.
Questioned by defence QC John Scott she agreed that her sister was not exactly a tidy person.
"The strange thing about this is: Arlene left a trail wherever she went but there is no trial this time."
Mrs Gillies was also questioned about Arlene's rings - which her step-mum, Catherine McInnes, said appeared in the bathroom nine days after Arlene's disappearance.
Advocate depute Alex Prentice QC, prosecuting, asked: "Could they have been there and you just didn't notice?"
"It is a possibility. I don't know," replied Mrs Gillies, who said she returned to the house soon after the discovery had been made.
She said: "I was in the living room and Cathy said: 'Look what I have found" and she took me into the bathroom."
Asked again if she had seen them before, Mrs Gillies said: "No, because I said to Cathy: 'Why have we never seen them before?' and that was the end of the conversation."
As Mrs Gillies began to give her evidence, Mr Prentice asked her: "Do you have a sister?"
"I HAD a sister," she told him.
Mrs Gillies said she had not seen Arlene or heard from her since April 28 1998.
The trial - now at the end of its third week - continues.