A distraught sister of missing teenager Arlene Arkinson walked out of an inquest as police defended their handling of the case.

Kathleen Arkinson sobbed as a former senior detective, who was part of a team that searched her home and dug up her garden, gave evidence to Belfast Coroner's Court.

Paul Bennett, a retired Police Service of Northern Ireland (PSNI) detective constable described chaotic scenes as police and army acting on an anonymous tip-off arrived at Ms Arkinson's home in Castlederg, Co Tyrone in April 1996 - two years after the schoolgirl went missing.

Ms Arkinson became hysterical, the court was told.

"She was abusive and was shouting, she was not opening the door. She threw a vase and other items towards myself and other officers," according to a statement made by the officer in July 1996 which was read to the court.

"She was roaring and shouting. She had a knife and said she would stick it through the first person through the door," it was claimed.

When uniformed officers did gain entry, Ms Arkinson, whose crying children were also standing in the hallway, was handcuffed and taken into the living room.

Nothing was found during the search of the property at Drumnabey Park or in a second search which used radar equipment in 2002.

Throughout the officer's testimony, Ms Arkinson shook her head and at one point had to be comforted by her solicitor. She left the courtroom visibly upset.

Mr Bennett said officers had been working to unravel the truth about Arlene's disappearance and could not believe "everybody and everything".

He said: "I believe that the police did everything they could have in a timely manner.

"There were a lot of inconsistencies with the people we were dealing with in relation to the police being told lies, people with alcohol problems and people with criminal records.

"The police were probing from the very bottom to try and establish the truth."

Meanwhile, details of an interview with Robert Howard - the prime suspect in the Arkinson case - were also given to the court.

Mr Bennett, who conducted the interview in September 1994 said the convicted child killer was evasive, reluctant to answer and did not like to make eye contact.

Even though more than 20 years have passed, he could still vividly recall the paedophile's demeanour, it was claimed.

Fifteen-year-old Arlene, from Castlederg, vanished after a night out at a disco across the Irish border in Co Donegal on August 13 1994.

She was last seen being driven away down a country road late at night with Howard.

Although he was acquitted of her murder in 2005 by a jury which was unaware of his conviction for killing south London teenager Hannah Williams, he always remained the prime suspect until his death in prison last year, aged 71.

During the course of the interview, Howard told detectives he had let the teenager off near a bar in the centre of Castlederg. He said he had returned to Patricia Quinn's home, made tea, rolled a cigarette and went to bed.

He also told police he had seen her being driven about in a sky blue coloured car by a man in his 20s the following day.

Howard refused to sign his statement on the advice of his defence solicitor, the court heard.

Meanwhile, proceedings were adjourned after lawyers for the Arkinson family called for the disclosure of some confidential police documents which could identify individuals who provided the information that led to the search of Ms Arkinson's home.

The Arkinsons' legal team have declined to continue questioning Mr Bennett and his superior who was due to appear on Wednesday, because of the ongoing dispute over the PSNI's Public Interest Immunity application.

Grounds for PII applications include matters of national security.

While the Government has obtained such immunity on sensitive papers relating to legacy terrorist cases in Northern Ireland, doubt surrounds why such issues would be at play during an inquest into the death of a missing schoolgirl.

Kathleen Arkinson and her former partner Stephen Walsh have requested to know the persons, adding that they deserve to know who tried to ruin them.

However, during previous hearings it was claimed that police did not know the identity of the informant who provided the tip-off.

The coroner, District Judge Brian Sherrard, has yet to formally rule on the contentious PII issue.

The hearing has been adjourned until Wednesday.