A company owned by the buyer of Britishvolt has been raided by the Australian authorities, throwing the future of UK battery-making further into doubt.

Britishvolt, based in Blyth, Northumberland, and which the UK government lauded for its potential role in British battery production and UK-built electric vehicles before it fell into administration, was bought by the Australian entrepreneur David Collard earlier this year.

On Friday, the Australian federal police attended the North Geelong offices of Scale Facilitation, a company founded by Collard who is also its chief executive, according to the Australian, which first reported on the raid. They wore blue gowns and gloves and focused on the seizure of IT and communications equipment.

Staff at Scale Facilitation have also gone unpaid in recent weeks, according to recent reports in the same newspaper, causing concern about its cashflow.

The police were acting on behalf of the Australian tax office, which has been investigating another business owned by Collard, SaniteX. It shares North Geelong offices with Scale Facilitation, which was founded by Collard and which now owns parts of Britishvolt. SaniteX also provides services to Scale Facilitation and some of the entrepreneur’s other businesses.

A spokesperson for Scale Facilitation said that it denied any wrongdoing, in a statement issued to newspapers.

Recharge Industries, a subsidiary of Scale Facilitation, bought Britishvolt after it fell into administration in January this year, reviving hopes for UK-made batteries and future car production in the country.

The development risks coming as a blow to the UK’s efforts to find a foothold in the global race to build electric cars at scale. It faces fierce competition and growing subsidies from the far larger government resources and domestic markets of the US, EU and China.

The timing was also sensitive for Collard, who has been seeking financing to help revive the Britishvolt endeavour in recent weeks. He had also discussed building a similar project in Australia, in Geelong.

Britishvolt was once valued at close to £800m, but collapsed worth just a tiny fraction of that sum, with one valuation by a bidder earlier this year placing it at £32m.

The raid by the Australian authorities may also raise questions for the major audit company EY, which is a creditor for Britishvolt, but also acted as its administrator, after it chose Collard’s Recharge company as the preferred bidder for the battery-maker.

The planned location for a revived factory build, which is estimated to require £3bn to complete, in Blyth, Northumberland was considered an important boost for jobs in the area. In December 2020, when the British prime minister, Rishi Sunak, was chancellor, he tweeted support for Britishvolt’s site claiming it would bring 8,000 jobs to to region.

Scale Facilitation has been approached for comment by the Guardian. A spokesperson for the company told other newspapers in a statement: “We have and will continue to fully cooperate with the Australian Taxation Office and now the AFP. We deny any wrongdoing and will continue working with our legal and other advisers to defend any matters arising from these discussions.”