Empty properties are said to be a problem

During the period covered by the report a total of 57,000 council houses were vacated, of which 35,000 took more than four weeks to re-let.

Rent arrears accounted for nearly 10% of the �456m owed by tenants to councils during the same 12-month period.

The proportion of those more than three months in arrears rose for the fourth successive year to 6.1% - almost one in 16 tenants.

According to the report, West Dunbartonshire was the worst offender for failing to collect rent arrears.

Nearly one quarter of its total rent revenue remained uncollected - a loss of about �2m.

Councils are suffering from this delay in payment created by years of benefit dependency

Alistair Gray, Cosla

Accounts Commission chairman Alastair McNish said much of the arrears would be collected in subsequent years but described the growing trend in tenant debt as "very worrying".

"The more councils are owed, the harder they have to work to collect it," he said.

"Council services rely on people paying their bills on time and tenants have a duty to do so.

"Despite the production of best practice guidelines and repeated calls for improvement, the latest information suggests that several councils have still not got to grips with all the issues surrounding the management of council houses."

A spokesman for Citizens Advice Scotland said many of the problems could be avoided by simplifying the housing benefit system.

'Vulnerable groups'

He said: "We find that administrative errors and protracted delays repeatedly result in Citizens' Advice Bureaux (CAB) clients suffering rent arrears, financial hardship and threatened and actual convictions.

"And it's often society's most vulnerable groups - the unemployed, the low paid, lone parents and the elderly - who find themselves thrown inadvertently into rent arrears.

"Citizens Advice Scotland wants to see a simplified single claims process developed to reduce processing and shorten processing time."

Cosla's housing spokesperson, Councillor Alistair Gray, said it was in the councils' own interests to pursue all outstanding debt.

'Councils are suffering'

He said: "We do regard non-payment of rent as a very serious matter and the vast majority have improved their collection rate and very few have got worse.

"Councils do attach great importance to this matter and recognise that they all need to make sure that they strive towards better collection rates."

Mr Gray said the introduction of tax credits had complicated matters, taking some tenants over the benefit threshold and meaning that they had to pay rent for the first time.

He added: "Councils are suffering from this delay in payment created by years of benefit dependency."