There have been calls for stricter regulations after the conviction of baby murderer Helen Stacey.

She is beginning a life sentence for fatally shaking five-month-old Joseph Mackin.

After a jury at Norwich Crown Court found her guilty, it emerged that she was a former prostitute who used a fake name to be included on Norfolk County Council's approved childminder list.

The Social Security Secretary Harriet Harman and Education Secretary David Blunkett are "looking at the feasibility" of a register, the Department of Social Security confirmed.

Ms Harman said the government would examine the issues raised by the Mackin as a matter of urgency, acknowledging the existing regulatory system had failed.

The move came despite the government's Better Regulation Task Force rejected the idea of registering nannies or nanny agencies.

Hidden past

BBC correspondent Bob Sinkinson at Norwich Crown Court

The judge, Mr Justice Blofeld, called for an inquiry into how Stacey managed to conceal her criminal past from social services officials.

Stacey, 41, failed to reveal that she had convictions for prostitution and theft when she applied to become a registered child minder.

Deception: Stacey concealed criminal past when applying to be a registered child minder

She also failed to inform officials that one of her children from her first marriage had been taken into care and the other two had been put up for adoption.

These facts would have debarred her from the scheme, but checking procedures relied on applicants supplying full and correct information.

The Director of Norfolk Social Services David Wright said the child minder registration system had already been tightened.

He said extra checks on marriage certificates and with doctors were already being carried out.

Solicitor Stewart Hanley: "Mr and Mrs Mackin don't want Joseph to have died in vain"

He added: "If we had been made aware of her history, she would not have been registered, but Ms Stacey did not give us the full names she had been known by.

"All we needed was the truth about her names.

"We can use our best endeavours but we can never guarantee 100 percent."

Solicitor Stewart Hanley: "Mr and Mrs Mackin don't want Joseph to have died in vain"

The dead infant's parents, Corinne and Anthony Mackin, say they will push to establish whether Stacey was correctly vetted by social services.

Their solicitor, Stewart Hanley, said: "Mr and Mrs Mackin do not want Joseph to have died in vain and will therefore continue their efforts to establish whether adequate checks were undertaken by the authorities as to Helen Stacey's registration as a child minder."

Some MPs are calling for a national registration scheme for all child care professionals.

Liberal Democrat women's spokesman Jackie Ballard said: "A register will be proved worthwhile if only one child is saved."

"People wishing to set up as a childminder or to run a playgroup need to be properly inspected and regulated.

"Yet somebody with a serious criminal record is perfectly able to establish either a nanny agency or work as a nanny in someone else's home without any controls whatsoever."