James Bulger's mother: Killers were rewarded for their crime

The mother of murdered toddler James Bulger says his killers were not punished but "rewarded'' for their horrific crime.

"I've never had justice for James.''

Jon Venables and Robert Thompson were given new identities and granted lifelong anonymity when they were freed on licence in 2001.

Denise Fergus said she never wanted them jailed for the rest of their lives for the torture and murder of her two-year-old son in Liverpool in 1993, when they were both 10 years old.

But speaking in a new documentary Ms Fergus said: "I've never had justice for James.''

She told Sir Trevor McDonald: "I never said 'lock them up and throw away the key'. I thought doing a proper sentence in a proper prison would be justice for James. But that never happened.

"They never got punished for what they done. In fact, if anything, they were rewarded.''

Venables was returned to prison in November, having been charged over indecent images of children for a second time.

Ms Fergus said: "I did say that if they weren't punished properly, then they would go on to re-offend and that's exactly what happened with Venables.''

The documentary, James Bulger: A Mother's Story, will be broadcast on ITV on Thursday night, 25 years after the toddler was abducted from Bootle Strand shopping centre.

His mother told how it was a "last-minute decision'' to go shopping that day and "the first time I left the buggy at home''.

"I let go just to get the purse out of my bag to pay for what I was buying and when I looked down as I was handing the money over, I looked down and he's gone - that's how quick it was,'' she said.

Ms Fergus described how "panic'' set in as she frantically searched for missing James.

But when CCTV emerged of his abductors she thought: "Kids aren't going to harm another child.''

Retired detective superintendent Albert Kirby, who led the Bulger murder inquiry for Merseyside Police, said: "When I was doing the briefings it wasn't uncommon for me to see some of the officers visibly shaken by what happened, crying.''

Another officer told how Ms Fergus "dropped to the floor'' when she found out about the death of her child.

"I just blanked out. I just remember, when I come round there were loads of people around me,'' Ms Fergus said.

"I'm just thinking 'it can't be true. It can't be happening'. You know, one minute they're going to come through that door and say 'you know what, we've made a massive mistake, here he is'.''

She added: "I think I was in shock like everyone else. No one expects two 10-year-old boys to take a child and do what they done.

"It's just beyond words really how two 10-year-olds could be so evil."