The mother of the man jailed in connection with Brighton's child cruelty scandal has spoken out.

She says her son should be locked up for life. The 69-year-old woman has spoken out for the first time to back the growing calls for a public inquiry.

It follows not guilty verdicts in the trial in which her son and his common-law-wife were accused of murdering three babies, her grandchildren. The mother, who lives alone on a council estate, backs the Argus call for a change in the law to make both parents or guardians culpable, even if only one committed the crime.

She said: "My son should be locked up and the key thrown away. They both should be. They were both with the babies and the experts say they were smothered. The pair of them lived for family allowance to spend on fags and bingo. The filth those babies were found in was disgusting. I would treat my dogs better than that."

The woman's 38-year-old son was jailed for six years at Lewes Crown Court for cruelty to the children, raping his two sisters and threatening to kill a social worker. His 26-year-old common-law wife was jailed for two-and-a-half years for cruelty.

Both were earlier acquitted of murdering the three babies, despite expert testimony that the boys, aged five weeks, six weeks and 17 months, had probably been smothered. The mother told police her husband had killed the babies with pillows because they were crying and had "deserved it".

Trial judge Mr Justice Moses ruled there was insufficient evidence to show both were in the room at the time of the deaths. He directed the jury to return not guilty verdicts as there was no evidence to say which of the parents, if either, was guilty. He said it was better to acquit both of them than convict an innocent person.

But the defendant's mother, who sat through the trial, condemned his decision. And she spoke of her anger following the sentences at the second trial. She added: "When I heard the sentences they finally got I was choked. I can't even think of him as my son anymore."

The mother says she realised her boy was rotten when he started stealing from her at the age of 11. He was shipped off to a succession of children's homes in Sussex before being sent back to her as a teenager. The relationship continued to deteriorate and she has had little contact with him in the last ten years.

However, she cannot understand why the social workers involved with the family did not take action sooner. She said: "This was going on for five years, why did nobody stand in before? Surely they must have seen what was happening? If I had seen what was going on I would have done something. I loved my grandchildren. We need a public inquiry to find out what went wrong and find out who is to blame.

"For my grandchildren's sake it can't be left like this. I have kept quiet until now but I feel I must speak up and tell the truth about my son. He is an animal."