Interserve has sacked four executives who were involved in last year’s discovery of a £25m black hole in its industrial services division.

The company confirmed the departures but refused to name the individuals involved.

Another two senior directors, who were suspended during the investigation into the accounting irregularities, have been cleared and are back at work.

Interserve brought in accounting firm KPMG and the lawyer Linklaters to conduct a forensic review into what had gone wrong.

The investigation, which started last September, cost Interserve £8m. This amount was mostly because of the cost of professional services.