A city MP has attacked Birmingham City Council over a lack of information given to residents living in homes built on contaminated land.
Steve McCabe (Lab Hall Green) vowed to find answers to local people's concerns through the Freedom of Information Act.
Mr McCabe has written to the council's Data Protection and Freedom of Information department to outline his wish to look at every document produced in relation to the houses in Graith Close, The Launde, Bach Mill Drive, Willson Croft and Priory Road.
Exactly a year ago, experts discovered the soil was contaminated with deadly substances including arsenic, lead, cadmium and nickel, and children were banned from playing outside because of fears of infertility and damage to internal organs.
Last month, residents were told any possible decontamination process would only be given the go-ahead if the Government agreed to pay and families would therefore have to keep young children out of their gardens indefinitely if the issue was not settled.
They were puzzled by a map, suggesting some houses sandwiched between ones believed to be on contaminated land were perfectly safe.
Mr McCabe is now trying to find answers about exactly which houses are affected and the extent of council knowledge of the land being toxic before the houses were built.
He has openly criticised the council for its silence, following a number of calls from constituents left with little or no information about the future of their homes.
He said: "Here we have hundreds of residents, many of whom are unsure as to whether or not their properties are contaminated, living on arsenic and cadmium estates with no idea what is being done to fix it.
"Many residents are only aware of the problem thanks to media reports. But now the Council seems intent on muzzling them too."
Speaking last month at a meeting of The Priory Mill Action Group, member Linda Beech said: "We are working class people who just happened to buy a house on contaminated land.
"I think the council completely missed the point on how much of an effect this has on our personal lives."
Birmingham City Council refused to comment.