Police have been called in to break up a bizarre neighbourhood war at a trendy Perth coffee shop after a furious local allegedly used a megaphone to heckle diners.

An eight-month feud between the owner of Side Piece Deli, Sam Kaye, and nearby residents in the wealthy enclave of Swanbourne has escalated dramatically with complaints about noise, traffic, odours and customers blocking footpaths.

Mr Kaye, a recent Business News 40 Under 40 winner for his success in running his booming cafe empire, alleges neighbour Kerry Wells screamed expletives through a megaphone at the packed deli, alarming customers mid-meal.

Mrs Wells admitted she 'lost her cool' during the standoff and yelled 'shut the f**k up' toward the cafe.

'Mr Kaye banned me from the premises when I have asked for the cacophony in the rear alfresco to be toned down,' she wrote in an email sent to Town of Claremont councillors and The POST newspaper.

Mr Kaye confirmed two locals had been banned from entering his venue, alleging that residents retaliated by blasting disruptive static noise towards the venue for hours on end. 

Council records show Ms Wells had earlier complained about 'noxious odours' from the cafe, which opened in August 2025, prompting an investigation by the council in February.

Now the extraordinary feud is heading for a dramatic courtroom showdown, with the Supreme Court set to hear the latest twist next month. 

Luxury homeowner Ian Satchwell, who lives two doors from the café in a $5.5million home, is now pushing to shut it down, arguing its council approval was unlawful. 

A writ application filed by Mr Satchwell calls for its planning approval to be overturned and the popular cafe, which he claims is operating as a fast food restaurant, to cease operating altogether.

Mr Kaye said he never imagined his small cafe would end up connected to Supreme Court proceedings - describing his fourth hospitality venture as one of his most difficult to manage.

'What started as what we believed would be a typical neighbour concern, unfortunately, escalated over time into something much larger and more public than we ever anticipated,' he told the Daily Mail.

'From the beginning, our focus has simply been on creating a great local venue for the community while working closely with the Town of Claremont and complying with the relevant approvals and operational requirements. 

'We've made several adjustments and operational compromises along the way to be respectful of surrounding residents and to keep the peace.'

Mr Kaye said there have been some 'difficult and confronting' moments for staff and customers and anticipated the legal action could cost anything from $150,000 upwards to defend.

'What has genuinely surprised us has been the level of support from the broader community,' he said.

'We've had an overwhelming response from customers and locals who simply enjoy having a neighbourhood café in the area, and we're incredibly grateful for that support.

'We remain hopeful that, over time, relationships can improve and a more constructive path forward can be found for everyone involved.'

The council recently issued a permit to allow the cafe to have outdoor seating for four people on the footpath to address frequent complaints over long queues of customers spreading onto the footpath and neighbouring verges.

It has stated publicly it would be premature to comment on the case however it has previously stated the cafe is compliant under its local planning scheme. 

The Daily Mail contacted WA Police for comment however they said they were unable to comment on the allegations or how many call outs they'd had to the cafe. 

Ms Wells has also not responded to requests for comment.