'It's not upsetting,' says Oliver Woollford's mother after complaints to Ofcom about torture and school massacre stories

Television thriller Utopia has been hailed by some as a cult hit and berated by others for its violent storylines, including one about a school massacre just weeks after America's Sandy Hook tragedy. Regulator Ofcom has received 44 complaints about brutality, offensive language and a complaint about child actors being involved in scenes of adult content.

Yet the mother of Oliver Woollford, who plays an 11-year-old near-feral boy called Grant in the six-part Channel 4 show, has no truck with the critics. Hayley Woollford told the Observer: "We really enjoy watching it. There is violence in it, but my son has always known the difference between reality and fiction. It's not upsetting, it's not giving anyone nightmares."

In episode one, a cowering seven-year-old boy is executed by one of the maniac killers with a gas inhaler who enters a comic shop, after an adult is beaten to death with an iron pipe and two other adults have been gassed. It moves onwards to an extended scene of torture involving chilli, bleach and a teaspoon applied to a character's eyes.

Thirty-seven of the Ofcom complaints relate to the school massacre, in which the same killer opened the third episode by shooting teachers and children. Then a schoolgirl called Alice sees her mother shot dead at close range: this character opened episode four last week, screaming uncontrollably.

Woollford, a warehouse operator, said: "There is never anything violent made in front of my son, or the little girl in it. My son is aware about makeup and special effects. It's been an amazing experience, we've learned so much. It's good to learn how television is made, it isn't all about actors, it's about everything else as well, a big eye-opener. My perspective is that people need to be made aware of that before they complain. I've had this experience, but I was a bit ignorant about television before."

Woollford, a lone parent of four children, added: "I'm on a low income, he [Oliver] needs this. We live on a council estate in Newark, Nottinghamshire, he goes to the local school. There are not a lot of opportunities for children in a town like this. It's football for boys, dancing for girls, that's it."

Oliver, now 14, was talent spotted in year six of primary school when a theatre company did workshops at his school. "They gave him an application form for the Television Workshop in Nottingham. I couldn't afford to drive him to Nottingham and pay the fees, but the teacher let him go free until he started earning. I took him to a lot of auditions. I had a struggle to pay for petrol and everything. We have travelled all over the country," said Woollford.

Oliver won his first substantial part last year in BBC1's Blackout drama about a corrupt council official, alongside Christopher Eccleston and picked up an award.

Utopia breaks the mould of average TV dramas on TV by attracting younger, male and affluent viewers. A third of the audience are aged 16 to 34. Male viewers compose 52% of its audience compared with the Channel 4 average of 46%, and 44% for television in general.

It is more appealing to young adults than Channel 4 hit Homeland and beaten in the youth stakes only by Channel 4's This Is England.

Jane Featherstone, the executive producer of Utopia, said: "The drama is exploring the dehumanising effect of brutality on children. It is a stylised piece, but it also shows the consequences of violence, and that becomes clear across the entire six episodes.

"It has to be viewed as a whole. I don't feel there is anything gratuitous about the violence in Utopia. At the end, the writer, Dennis Kelly, has things to say to the world."

Featherstone, who oversaw the hugely successful Spooks added: "We followed, to the rule, the regulations covering child actors. And on screen, you do not see as much as is implied."

• This article was edited at 23.28 GMT on Saturday 9 February to remove a factually incorrect reference to a killer sparing a small boy's life