Dating back to the 1920's, it could be the first time the prominent business has been left without someone to run it, as the current owner, Bob Loughnan, jumps ship.

The heavy metal grills protecting the entrance were closed permanently on Friday afternoon, leaving the landlord of 20-odd years, Peter Berry, in the lurch.

"It was just getting too tough for Bob to run," Mr Berry said.

He said Mr Loughnan had been fighting to keep the supermarket open despite a dwindling customer base, following some of the biggest-ever changes to the Northern Territory's alcohol policies.

"The police presence with regards to the sale of liquor have driven people out of town and the supermarket really felt it," Mr Berry said.

"Bob was trying to run the store without selling alcohol for the past three months, but he just wasn't getting enough customers.

"Katherine and Tennant Creek have these special rules and Darwin is only three hours away, so that is where people are going."

Yesterday, following the announcement of a comprehensive evaluation of the NT's alcohol harm reduction measures, Minister for Health, Natasha Fyles said, "there are early indications that our policies are having a positive impact."

The NT Government says its Alcohol Harm Minimisation Action Plan, which included the introduction of a floor price on alcohol, and a contingent of liquor inspectors manning bottle shops, was designed to tackle alcohol related violence and crime by targeting problem drinkers.

"We are putting Territorians first with nation-leading alcohol policy and legislation to make our community safer," Ms Fyles said.

The closure follows a long string of disturbances to the business, including break-ins and vandalism.

Just last year, three males were arrested by Katherine Police and charged with unlawful entry to the supermarket, significant damage to the property and stealing.

The daring break and enter to one of the most secure businesses in town came after it had already been ransacked days earlier, leaving it down thousands of dollars.

Mr Berry said the closure is a blow to the once bustling main street.

"Katherine can't afford to lose more stores, it doesn't have the vibrancy it used to," he said.

The landlord is already in the process of looking for a new owner and is pushing for a major chain to take over the decent sized, and centrally located space.

He said he would welcome competition to Katherine's main supermarket, Woolworths, which during peak tourist season is overcrowded.

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