Burns Anderson has been forced by the PIA to double the number of pension misselling cases it must review after it was found that the network had left out 509 non-priority cases.
Latest Treasury figures reveal that the 200-member network has 922 cases to review, with just 15 per cent dealt with.
Last month, the figures showed that Burns Anderson had 413 cases and had cleared up 26 per cent.
Compliance director Ian May says the network excluded the 509 cases because they are non-priority but, following a visit from the PIA, it has been forced to reconsider.
May says: "The cases are non-priority but we went to them all saying that if you would like a review, let us know."
The PIA does not impose deadlines on companies for dealing with non-priority cases but they are included in the Treasury's figures.