Some house sales are falling through because of delays to property searches during the Covid-19 pandemic, a solicitor has warned.
Solicitors ask local authorities to carry out the searches on issues including planning and traffic.
Telor Dyer, a residential conveyancer in Carmarthenshire, said waiting times in some parts of Wales had doubled to 30 working days.
Pembrokeshire council said it had a backlog after the lockdown in March.
The Conveyancing Association warned the backlog facing local authorities was "becoming a significant issue".
Local authority searches show details about a property such as whether it is a listed building or in conservation area. These details can have an effect on future planning works to the property.
Not a 'unique issue'
Pembrokeshire council, one of the local authorities facing difficulties, said it would not be processing any new searches "other than those deemed urgent" due to its backlog.
Issues, the council said, included the inability to access County Hall, where searches have to be checked against maps stored there, followed by the unprecedented demand in property sales since the lifting of restrictions.
But a council spokesperson said this was "not an issue unique to Pembrokeshire - many other local authorities are working to a 40-day turn around".
The spokesperson said their usual turnaround for searches was seven to 10 days, but due to the pressures on the service they have implemented an average 20-day turnaround to work through the backlog.
"The matter is being kept under constant review," they said.
Residential conveyancer Mr Dyer, based in St Clears, said he had seen significant delays and that they were down to a property boom and staff shortages.
"Usually, we anticipate, searches would take 10 to 15 working days, but now it's taking 30 working days," he said.
"There's nothing we can do speed things up. We have had sellers pull out and there's nothing we can do about it."
Rebecca Goldsworthy, director and head of residential property in south east Wales for JCP Solicitors, said local searches were an important part of the buying process.
"There's nothing we can do about that other than advise our clients there is a bit of a wait. We are concerned another lockdown period will cause further delay," she said.
"A delay with searches will hold up the chains."
'Relieve the pressure'
Meanwhile, the Conveyancing Association has called on the government to extend the holiday on land transaction tax.
The starting threshold for the tax has been increased from £180,000 to £250,000 for the main residential rates until 31 March 2021.
Similar holidays have been introduced for property sales taxes in the rest of the UK.
Operations director Lloyd Davies said its member firms, who undertake about 30% of all property transactions in England and Wales, were 130% to 150% over capacity at the moment.
He said the holiday should be extended to at least 2022 to "relieve the pressure", or there would be a large number of transactions that do not meet the deadline.
The Welsh Government said the temporary changes to land transaction tax were specific time-limited measures intended to support the housing market and broader economy in Wales during the remainder of this financial year but were kept under regular review.