Bosses at five-a-side football pitch operator Goals Soccer Centre have uncovered "improper behaviour" by a number of senior staff stretching back nearly nine years.

The revelation means the East Kilbride-based company is unlikely to file its accounts by the end of September, which would have allowed shares to start trading again.

Shares, of which Mike Ashley's Sports Direct owns 19%, have been suspended since March after bosses revealed a £12m tax dispute over unpaid VAT. Friday's announcement means the company is likely to be delisted.

Goals, which has three centres in Scotland, said: "The company regrets to announce that, following ongoing detailed investigatory work into the historic accounting policies and practices used by the company in the recognition of revenue and the preparation of financial statements, it has become very recently evident that there has been improper behaviour within the company.

"This has involved a number of individuals for a period since at least 2010.

"Due to these initial findings, there is material uncertainty in relation to the historic financial statements published by the company.

"The directors do not now believe this timeframe for the audit is achievable and, coupled with the findings above, no longer expect the ordinary shares in the company to resume trading."

The 2018 audit has now been suspended, it added.

Sports Direct has already demanded Goals bring in corporate investigator Kroll to carry out a "cradle to grave" probe of the business, but this has been rejected.