More than 6,500 homeowners have had to pay more property tax to the Revenue Commissioners.

It has hit those who sent in a low self-assessed figure for the value of their home, and then sold the property for far in excess of that.

The Sunday Times reports that even where homes were sold for 15% above the self-assessed value outside Dublin - and up to 25% in the capital - the sellers escaped higher payments.

Revenue says it has challenged hundreds of self-assessed valuations of properties.

As part of the process, homeowners must show Revenue how they reached their final valuation.

But the paper adds that there is no additional liability where there is evidence of the original valuation - and where full payment is made.

Tax revenues were up €1.2bn more than expected in 2014, but the one exception was the property tax.

But this was said to be due to bad estimates on the part of finance chiefs, rather than people not paying it.