The penalty is the largest yet imposed by the FCA for mishandling of PPI complaints, and is intended to reflect the conscious concealment of information from the Financial Ombudsman Service, the body that adjudicates PPI claims. Had Clydesdale not settled the case early, the bank would have incurred a fine of £29.5m.

Between May 2012 and June 2013, individual members of Clydesdale’s PPI complaints division are said to have amended a number of computer printouts to obscure relevant documents from the FOS. Staff also deleted information referring to PPI charges from printouts listing products sold to certain customers.

Such conduct meant that over 42,000 PPI complaints were unjustly rejected, and over 50,000 complainants received inadequate compensation between May 2011 and July 2013 – meaning almost 73 per cent of the 126,600 complaints the bank received during this period were mishandled.

“The fact that Clydesdale misled the Financial Ombudsman Service by providing false information about the information it held is particularly serious and this is reflected in the size of the fine,” commented Georgina Philippou, the FCA’s acting enforcement director.

“We have been very clear about how firms should treat customers who may have been missold PPI. In ignoring documents it held which were relevant to its customers’ complaints, Clydesdale failed to treat its customers fairly.”

If you believe you’ve been mis-sold PPI and would like to claim, please visit the Your Money guide.