High lead levels in baked clay eaten during pregnancy
High levels of lead and traces of arsenic have been found in baked clay traditionally eaten by some African and Asian women during pregnancy.
Almost 400kg (880lbs) of the clay cubes were taken from shops in Birmingham by trading standards officers.
Raids were carried out after tests conducted over the weekend on samples of the clay, known as sikhor, found potentially dangerous levels of lead.
The clay is thought to have come from a wholesaler, the city council said.
A search of the wholesaler's premises, in the Soho Hill Road area of Birmingham, discovered 33 boxes of the cubes, all of which were taken away.
Lead levels in all the samples were found to be 24mg per kg, 16 times higher than the acceptable level for human consumption in the UK.
The council said exposure to lead by pregnant women, infants or children posed a risk to the development of the brain.
A spokesman for the council said in many parts of the world eating the baked clay was an ancient tradition among pregnant woman with cravings, and sikhor tablets are fairly common in many Asian stores in the UK.
The council said much of the sikhor on sale had not gone through the usual process required to be judged fit for human consumption.
Councillor Neil Eustace, chairman of the public protection committee at the council, said the results of the test purchases were "concerning".
"In order to protect the health of consumers within the city, and especially their unborn children, we had no choice but to act decisively to remove as much of this product as possible from the city's shelves."