A couple have been given the green light to take legal action against the previous owners after unwittingly purchasing a house infested with Japanese knotweed.

Dr Marie Donnelly and John Busby bought Firth Lodge, a four-bedroom house in Auchendinny, near Roslin, Midlothian, for just over £602,000 in 2021.

The brochure provided by the estate agency marketing the property failed to mention that the house was plagued with Japanese knotweed; removing the plant with its thick, woody roots costs thousands of pounds.

The previous owners, Kim and Mark Blair, declared that as far as they were aware the property, including the grounds, was not affected by rot, damp, woodworm or other infestations. However, they accepted that they knew about the presence of knotweed and had attempted to remove it without success.

Sheriff Christopher Dickson at Edinburgh sheriff court concluded that the buyers should have been informed.

He said: “I considered the presence of Japanese knotweed on a property in sufficient numbers could properly be described as an infestation and that a Japanese knotweed infestation was a harmful thing or matter which could commonly adversely affect a property, which included adversely affecting a physical building.

“Indeed [the Blairs] admit that JK ‘is a pest plant which blights gardens and damages structures’. They admit that they were aware, during their ownership of the property, that the property contained Japanese knotweed.

“[Donnelly and Busby] aver that the property contained a substantial amount of Japanese knotweed including knotweed that was near to the dwelling house on the property.”

He found in favour of the present owners and allowed them to proceed with legal action against the former owners based on a “breach of the terms of sale”.

In 2019, an English court awarded a homeowner £50,000 in damages from his surveyor after he had to pay £10,000 to clear the problem. The court ruled that his ability to use the land his house was on was hindered by the plant.