A highly toxic plant capable of causing serious skin burns has been found close to a public footpath in East Malling.

Giant hogweed - which can grow to heights of 15ft - emits a sap if the stem is broken that burns skin and can leave permanent scar.

Daniel Markham discovered the plants while out walking his dog Oscar.

He said: "They are on land belonging to the research centre (NIAB EMR) at East Malling, between Rocks Road and Sweets Lane in East Malling.

"Some are about 12ft tall. I recognised them as Oscar was running straight towards them, obviously I called him back at once."

Contact with the plant causes the skin to blister, forming painful lesions, with the effects sometimes continuing for years afterwards.

The plant contains furocoumarin, which makes skin extremely sensitive to sunlight - a condition called phytophotodermatitis.

Mr Markham said: "I know these plants are highly dangerous, so I've been posting on social media warning walkers to stay well away from them."

Members of the public who discover the plants in the countryside or in their own gardens are strongly advised not to try to grub them up themselves, but to call in an expert.

If the sap gets onto your skin and then you are exposed to the sun, your skin can blister very badly and the blistering can recur over months and even years. This is known as phytotoxicity.

Andrea Griffiths from the Medway Valley Countryside Partnership (MVCP) said: “Giant hogweed can be very damaging to the environment. It's an invasive plant that destroys bio-diversity.

"It also causes burns sometimes for years afterwards. If you have been in contact with it, your skin can still react badly to sunshine. It is nasty stuff."

The plants are most commonly found next to waterways and MVCP has been carrying out a concerted effort to rid them from the riverbanks of the River Medway as it flows through Tonbridge and Maidstone for the past 11 years.

She said: "It's always a huge operation for us. We wear protective clothing and use a very directed chemical weed-killer to destroy it.

"Ideally you would dig up the roots, but that is not always possible along the riverbanks where access is often very difficult."

In its first year of operation, the MVCP found and destroyed more than 20,000 plants, but Ms Griffiths said: "It is an ending task - you only have to miss one and it will come back.

"There's also a very limited window when you can tackle the problem - from late March when they start to appear till early July when they seed."

She said: "Each plant can produce 50,000 seeds so you need to get to them before the seeds spread."

But she said: "We are getting on top of it. Last year we found only 8,500 plants and this year hopefully it will be fewer."

Giant Hogweed (Heracleum mantegazzianum) is native to central Asia and the Caucasus mountains and was first introduced to the UK in the 19th century as an ornamental garden plant.

The Wildlife and Countryside Act 1981 made it illegal to plant or cause giant hogweed to grow in the wild, and it is also listed under the Invasive Alien Species (Enforcement and Permitting) Order 2019.

Spencer Diprose is the estate manager for the East Malling Trust, which owns the freehold of the land where the East Malling plants have been found. He said: "There is some Giant Hogweed on private land, approximately 35 to 40 metres away from the public footpath."

Mr Diprose said: "No members of the public should be straying off the public footpath and coming into contact with these plants.

"Our tenant is aware of the plants and has instigated a successful non-chemical control of the flowering plants last year – which has resulted in no regrowth of those plants this year.

"They now have planned a control programme for the few plants which were seedlings last year (and therefore missed) and this will be undertaken in the coming days now that the plants are in flower.

"We expect to be doing similar checks in the coming summers to ensure the control programme is complete."