Love Shaft is set in a lift where a young man or woman looking for a date is presented with a series of potential partners as the lift stops on each floor.
The aim is for the candidate to find a date before the lift reaches the penthouse floor, and they are quizzed along the way by a disembodied voice called 'Lift', while their family and friends monitor their progress.
A complainant alerted Ofcom to episodes of Love Shaft aired on June 2, 9 and 23, whicbh all featured some rather racy comments and innuendo exchanged between the contestants.
This included a contestant expressing his desire for a girl with "massive tits"; some sexually suggestive comments about a pineapple; a girl being asked to "wap her baps out"; and a 12-year-old boy dressed as a headmaster asking the contestants: "How old were you when you popped your cherry?"
Channel 4 attempted to argue that the tone of Love Shaft was meant to be "cheeky, witty and full of entendre and risqué banter, especially from the voice in the lift".
The broadcaster claimed that the programme was appropriate for a pre-watershed transmission as "the content would not have gone beyond the generally accepted standards" of the 16- to 34-year-old T4 audience.
Channel 4 also noted that the show was originally aired on E4 in May 2012 at 7.30pm.
However, Ofcom considered that the "cumulative effect of all such references throughout the episodes was to heighten the adult nature and sexual theme".
The regulator therefore judged that Love Shaft was unsuitable for children, and so the programme was inappropriately scheduled on a Saturday morning.
"We noted the BARB viewing data for these programmes which showed that a significant number of children were viewing," Ofcom said.
"There were 11,000 children aged 4-15 (9.2% of the total audience) watching the episode on June 2; 14,000 children (11.8% of the total audience) watching the episode on June 9; and, 6,000 children (8.2% of the total audience) watching the episode on June 23.
"Ofcom therefore noted that, while the material was aimed at a more adult audience, it was broadcast on a Saturday morning when children were watching, some possibly unaccompanied."
It added: "Ofcom considered the content, featuring a continuing sexualised theme, was not suitable for broadcast at 10.35am and 9.50am respectively, on a Saturday morning."