KEY POINTS:
Police have officially warned an elderly Marlborough woman - convinced Scott Watson did not murder Ben Smart and Olivia Hope - to stop contacting Ben's mother.
Mary Smart is equally adamant Watson is guilty of the murders almost 11 years ago, and confirmed she had called police after Rosa Oliver, 87, phoned her last week.
Oliver said days after Smart told her not to call again, two officers arrived at the Waterlea rest home in Blenheim with the same warning.
"I was in the middle of my chess game so I couldn't be bothered with them. I never used to be a swearer, but I swore that afternoon. They were three times bigger than me; I'm five foot nothing," said Oliver.
"I rang the station afterwards, and I said: 'I thought the police were short of staff, but you send two officers around to tell off a little old lady?'
"But I'm not afraid to stand up to authority, when I know I'm right.
"And I know I'm right about Scott Watson and I'm passionate about justice."
Smart confirmed she asked the police to speak to Oliver because she was being a "nuisance" but declined to comment further.
Oliver told the Herald on Sunday she had approached Smart in a supermarket in 1999 not long after Watson was found guilty.
Two police officers were sent to warn Oliver then, but the retired schoolteacher says she had not called Smart since.
Smart said the "right man" was behind bars, which puts her slightly at odds with the father of Olivia, Gerald Hope, who has admitted growing doubts about Watson's conviction.
"Oh absolutely," said Mary Smart when asked if she thought Watson was guilty.
"I defy anybody who sat through the court case to say otherwise, including the Watsons. There's been absolutely no mistake."
Watson's father Chris and high-profile defence lawyer Greg King are putting the finishing touches on a petition to the Governor-General, who can, in consultation with the Ministry of Justice, recommend Watson be pardoned or refer the case back to the Court of Appeal.
King said the jury accepted the Crown case at the first trial in 1999 but evidence unearthed since was the key to overturning the convictions.
Meanwhile, Chris Watson has challenged the integrity of a police inquiry into allegations Deputy Police Commissioner Rob Pope swore misleading affidavits during the investigation.
Watson laid the complaint in 2004 but it was not actioned until Act party leader Rodney Hide and the Herald on Sunday questioned Police Minister Annette King in March.
Chris Watson said he was concerned that police had never interviewed him as the complainant.
Police spokesman Jon Neilson said Watson was not interviewed because all the relevant information was outlined in the complaint. An independent lawyer had reviewed the report by Detective Inspector Ross Pinkham in April and "a couple of matters" were expected to be resolved soon.
