Parents are worried a highly poisonous plant being sold in gardening stores could lead to the death of a child.

B&Q is among retailers selling the deadly nerium oleander, which contains enough poison in one of its leaves to kill a human.

There have been reports of 850 poisonings in the US attributed to the plant and scores of animal deaths, particularly among cattle that grazed on it.

Mother Angela Reeves, of Crabtree Avenue, Brighton, thought she had picked up a bargain when she bought two of the £3.98 plants at B&Q in Lewes Road, Brighton.

But after looking up planting advice on the internet she discovered they are actually one of the most toxic plants around.

She said: "There is a very small warning on the side of them, saying toxic'. But I certainly didn't notice it.

"My worry is that people will be planting these in their gardens this summer and their children will rub against them or put their leaves in their mouths.

"Even just rubbing against them can prove harmful."

Experts at Kew Gardens said the oleander is deadly.

A spokesman at Kew Gardens said: "The harmfulness of oleander is pretty well documented and for the unwary gardeners it can prove dangerous.

"There have been cases where people have been made ill and even killed by it.

"It absolutely should be kept out of the way of children and animals. But at the same time it is a beautiful plant and it would be a shame if it was demonised.

"As long as it treated with respect and planted knowledgeably there is no reason to worry."

All parts of the plant are poisonous and induce symptoms such as nausea, vomiting, stomach pain, dizziness, slowed pulse, irregular heartbeat, dilation of pupils, bloody diarrhoea and drowsiness when ingested.

In extreme cases it causes cardiac arrest leading to death.

B&Q warns customers about the toxicity of the oleander when people buy it.

A spokesman for the firm said: "The safety of our customers is paramount and there are clear warnings about the toxicity of oleanders printed on the sides of pots we sell them in.

"This is also backed up in store by our trained staff who are on hand to offer further advice.

"We would recommend, as with any toxic plants, that they are kept out of the reach of children."

The oleander is one of a number of plants common in British gardens that are poisonous.

Experts recommend seeking urgent medical attention if ingested.