Deloitte’s review of Alfred McAlpine’s Slate subsidiary earned the Big Four firm £6m, it emerged this week.

It was drafted in to conduct the probe, Accountancy Age revealed earlier this year, covering four years of activities at the construction giant’s subsidiary. An internal audit had earlier uncovered serious accounting irregularities at the division.

The scandal, which is expected to cost McAlpine £30m in 2007, caused finance director Dominic Lavelle to hand in his notice, despite not being involved in the deception: ‘Given that it happened on his watch he decided to do what he felt was best,’ said a spokesperson.

Chief exec Ian Grice said that there was no suggestion that auditors PricewaterhouseCoopers had failed in not picking up the frauds, because of the level of deception involved.