EDF Energy has been criticised after a 13-year-old-boy won a competition that was part of a campaign to attract teenage girls to the fields of science, technology, engineering and maths.
Children were asked to think of ideas for a connected home bedroom product.
EDF said that while its Pretty Curious programme is still aimed at girls, the UK competition was later opened up to all 11 to 16-year-olds.
It continues to share the same website and branding as the girls' scheme.
The BBC understands that the decision had been made to open the competition up to both genders in the interests of fairness, and that the contest attracted "a couple of hundred" entries.
Following three events held in the UK for girls last year, the contest was extended online and made available to boys as well.
The winner's idea was for a games controller which harnesses kinetic energy from thumb action using wind-up triggers.
Three of the four runners-up, whose ideas included smart curtains, a smart fridge and a sleep monitor, were submitted by girls.
"We were really impressed with the ideas which were submitted. It's exciting to see so many young people getting involved in this type of initiative and engaging with Stem (science, technology, engineering and maths). We hope more young people will be inspired to pursue Stem subjects at school and consider Stem careers in future," said Amy Edmundson, an electrical maintenance technician at EDF.
"Congratulations to the winner - but I'd love to hear from EDF how the winning solution meets their stated aim for the competition," said computer scientist Dr Sue Black OBE. "It is taking me a bit of time to work out how this result will change girls' perceptions of Stem."
In a tweet, EDF said that while "the aim of #PrettyCurious was to encourage girls into #STEM, the #PrettyCuriousChallenge was a gender-neutral competition".
It added: "The winner was shortlisted by a panel of judges including the all-female winning team from our #PrettyCurious Glasgow workshop."
Suw Charman-Anderson, who founded the annual celebration of women in Stem, Ada Lovelace Day, told the BBC she had had reservations about the Pretty Curious campaign from the beginning.
"EDF Energy chose to link appearance and interest in Stem through the title of their campaign, despite many people pointing out that it was demeaning to girls," she said. "Rather than challenging stereotypes, the focus on girls' looks rather than their intelligence reinforces them.
"EDF Energy have failed to understand both the nature of the problem [of women in Stem] and the negative impacts that their publicity stunt may well have on girls who took part with genuine enthusiasm and excitement."