Almost seven per cent of Australian mortgage holders have little or no equity in their homes, according to new research.Roy Morgan Research found that in 311,000 cases the value of the home was equal to or less than the amount owed on the mortgage, putting a significant number of people in financial risk if house prices decline or they are forced to sell their properties.The state with the highest proportion of mortgage holders "at risk" is Western Australia, where 9.2 per cent have little or no equity in their homes.Roy Morgan industry communications director Norman Morris said in a statement: "The mining boom and associated increase in housing demand in Western Australia, followed by the slowdown in the mining sector, is seeing the highest proportion of mortgage holders faced with little or no equity in their homes."In Queensland the proportion is 7.5 per cent, in South Australian 6.7 per cent, Victoria 6.3 per cent, Tasmania 6.1 per cent and in New South Wales 5.1 per cent.Households at risk tend to own low value properties. The average value of houses owned by all mortgage holders is $674,000, while the average value of houses owned by mortgage holders at risk is $478,000."Over 300,000 home borrowers having no real equity in their homes represents a considerable risk, particularly if home values fall or households are hit by unemployment. If home loan rates rise the problem would likely worsen," Morris said.