House prices "bounced back" in January, with the Halifax reporting a quarterly rise of 1.9% across the UK.
The measure compares prices in the three months to the end of January with the previous quarter.
According to the Halifax prices in January alone increased by 2%, compared with December - the largest January rise for six years.
And when measured on an annual basis, house price inflation increased to 8.5% - up from 7.8% in December.
For the last few months, house prices had been on a moderating trend.
"This bounce-back in house price growth in January coincides with reports of the first rise in mortgage approvals for six months in December," said Martin Ellis, the Halifax's chief housing economist.
Last week the Bank of England reported that mortgage approvals rose slightly between November and December.
However, some analysts have cast doubt on the figures.
"The 2.0% jump in house prices reported by the Halifax is hard to explain, and looks markedly at odds with other latest data and survey evidence," said Howard Archer, chief UK and European economist with IHS Global Insight.
The Nationwide Building Society reported that prices in January rose by just 0.3% compared with December.
Year on year % change
However, the Halifax said there was a good explanation for the unexpected rise in prices.
It pointed to further declines in mortgage rates, as well as the reform of stamp duty, which came in in December.
Under those changes, most people pay less duty when they buy a house or flat than they used to.
The Halifax's Mr Ellis said the fact that wages are now increasing faster than inflation was another factor in boosting prices.
However, he said that prices at this time of year tended to be very variable.
"The monthly figures in January can be particularly volatile due to the lower volumes of activity at this time of year, and there have been unusually large rises on occasion in the past, such as in 2007 (2.3%) and 2009 (2.4%)," he said.
The Halifax said that the average UK house price was now £193,130.