The developer behind the complex, the Bulum Group, is now awaiting approval for the boundary between the two blocks to be adjusted, so that it can be sure the so-called Yamaroshi complex is compliant with planning laws.

Mort Street's Officeworks store is located on the neighbouring block.

A Bulum Group spokesman said it has been forced to delay settlement on the project for 8-10 weeks while it worked to resolve the issue, which only came to light very recently.

Part of the Yamaroshi block is encroaching on the Officeworks block by five centimetres.

"To the best of our knowledge, and the knowledge of [builder] Chase Construction, construction was done so in accordance with the approved plans," the spokesman said.

"It wasn't until the building was virtually complete that the project surveyor alerted Chase to a boundary encroachment.

"After being made aware of the issue, we elected to delay settlement of the project to ensure the matter was resolved in full and to alleviate any unnecessary complications for the incoming owners."

Building into an adjacent property is unlawful under territory planning laws.

However, an Access Canberra spokesman said it was not investigating the apparent breach, after Bulum Group indicated it was already working on a resolution.

The developer self-reported the encroachment to the regulator on September 10.

The Bulum Group spokesman acknowledged the decision to delay settlement might cause "a minor inconvenience" for apartment buyers.

"[But] we are confident that it is the right decision, and ultimately one which will ensure that the end product is of the highest possible standard and free of any defects or legacy issues," he said.

"The impact on buyers due to this administrative manner has been at the forefront of concerns for us and the ACT Government, who all continue to work together in attempt to expedite the resolution."

The ACT Planning and Land Authority approved Bulum's plans for Yamaroshi in September 2015, paving the way for construction of 52 apartments, one floor of commercial space and two levels of basement carparking on land at 32 Mort Street.

Bulum Group is now waiting on the planning authority's assessment of an development application to adjust the boundary between the two blocks.

That would involve the transfer of 4 squared-metres of land from the Officeworks block to the Yamaroshi block, according to application documents.

The Mort Street Officeworks block is owned by a company called Pebruk Nominees Pty Limited, which lists world-renowned sports doctor Peter Bruckner and architect Diana Tapsall as its directors.

Led by Nik Bulum, Bulum Group been delivered a number of apartment and mixed-use complexes in Braddon in recent years, including the Ori and Nibu developments.

The developer's Branx apartment complex at 16 Lonsdale Street is under construction.

Bulum's Yamaroshi project made headlines in January 30, when a 3.7 tonne concrete panel fell 17 metres from the construction site, smashing the toilet block of a nearby mechanic's business and damaging cars.

Construction work on the development has since been completed.

The developer's spokesman this week it was "extremely excited to add Yamaroshi to an ever increasing portfolio of apartment buildings curated to push the standard of high density living in Canberra".