The office of the Financial Services Ombudsman heard more complaints last month than in any other month since it was set up.
The Ombudsman's review, which was published tonight, also shows that complaints about investment and insurance products remained at record highs during the last six months of 2010.
The review provides a detailed breakdown of complaints received and dealt with by the Ombudsman's office.
It shows that there was a 40% increase in mortgage related complaints during 2010, as the office dealt with over 7,200 complaints during the year.
Ombudsman Bill Prasifka says the number reflects the 'immense difficulties' facing consumers and the financial industry.
Almost half of the complaints received by the office related to the insurance sector.
Complaints about household insurance policies in 2010 doubled because of flooding and severe winter weather.
