In 2015, Aberdeen appointed PwC after having been with KPMG, while in May, Standard Life appointed KPMG, having been with PwC.

According to its 2014 annual report, Aberdeen Asset Management paid KPMG £1.5m in audit fees for that year, plus £600,000 for non audit services. Standard Life paid PwC a total of £7.3m in 2015. This was made up of a group audit fee of £3.7m, reduced from £4.7m the previous year because of the disposal of the company’s Canadian business.

The newly-merged fund manager confirmed the audit ‘would have to be addressed’.

A Stock Exchange announcement confirmed the deal's conclusion, following court approval for the merger last week.

The new business, trading as Standard Life Aberdeen, will manage funds worth approximately £670bn.

Having been agreed in March, the merger aims to make £200m in cost savings per year, while the firm will have a global workforce of 9,000.

The new company will be jointly led by co-chief executives Keith Skeoch, originally of Standard Life, and Aberdeen boss Martin Gilbert.

Overall, the combined business has 50 offices around the world, with clients in 80 countries.

Martin Gilbert said: ‘As ever our priority remains the delivery of strong investment performance and the highest level of client service. The merger deepens and broadens our investment capabilities, and gives us a stronger and more diverse range of investment management skills as well as significant scale across asset classes and geographies.’