A Sydney mayor insists there is no “cover up” from his council over Mascot Towers, after it was revealed engineers are still waiting on paperwork that may help them pinpoint the cause and prevent further damage.

It comes after residents and owners of the units were told part of the building appeared to be “moving in a downward motion”.

The 10-year-old apartment block was evacuated on 14 June after engineers became concerned about continued cracking in the primary support structure and facade masonry. Since then, residents of its 132 units have been forced to sleep elsewhere, with costs quickly adding up as authorities scramble to determine who is at fault.

Mascot Towers’ coordinating engineer has now identified a new issue along the northern and eastern boundaries of the complex.

It’s understood engineers have requested documents from Bayside City Council – including the original development application – but are yet to receive them.

The Bayside mayor, Bill Saravinovski, said a formal request was only made on Thursday – a week after residents were evacuated – and noted the documents were stored at a site on the New South Wales central coast. But he was unable to explain why they still had not been retrieved.

Without the documents, it is understood the engineers are somewhat helpless to stall the building’s deterioration, let alone work out what the issue is.

Saravinovski insisted “there’s no cover-up by Bayside City Council”. “Whatever documents we have on file will be made available,” he told reporters on Tuesday.

“My understanding is that we received a request last Thursday and we’re onto it; even if I have to get the general manager to drive up there to the central coast. Even I will drive up there.”

Saravinovski couldn’t guarantee the engineers would have the documents by the end of Tuesday.

It comes as the tower’s coordinating engineer identified a new issue along the northern and eastern boundaries of the complex.

“It appears that the building is moving in a downward motion,” an update sent to residents and owners on Monday night said. It did not elaborate on “downward motion”.

Two senior geotechnical engineers have been engaged and are visiting the site this week with help from Engineers Australia, according to the update. Internal monitoring has been expanded, while equipment to measure external movement has been set up.

The New South Wales government on Sunday announced a multimillion-dollar assistance package “until liability can be determined and these costs recovered”.

The package offers one-off emergency loans to cover up to $400 a night for temporary accommodation, for a period of up to three months. But it remains unclear what will happen if no one is found to be at fault or if insurance claims aren’t paid out.

When Gladys Berejiklian was asked to guarantee that residents themselves won’t have to pay the money back, the NSW premier was noncommittal.

“We’re actually working through those issues,” she said on Monday. “The engineers haven’t yet finished their assessments.

“Whilst there’s huge question marks as to who is accountable, I want to assure everybody the government will keep those who made those mistakes and haven’t done their job properly accountable.”

At the weekend the government promised the biggest shake-up of the state’s construction industry, including an annual audit of 30% of certifiers.

Berejiklian agreed the government’s decision to step in was “controversial” but said these were “exceptional circumstances”.

“We hope the residents will be back in their units as soon as possible but we don’t know how long that’s going to take and I don’t want anyone feeling extra stress about where they’re spending the night whilst this uncertainty is there,” she said.

The money for the loans will come from the interest accumulated in the NSW government’s rental bonds fund.