The Independent Television Commission also expressed concern at a storyline about under-age homosexual sex.

But after receiving more than 160 complaints about Queer As Folk, the ITC ruled that its programme code had not been broken.

The first episode in the Channel 4 series featured graphic scenes of homosexual sex between a promiscuous 29-year-old man and a 15-year-old boy.

The ITC criticised the "celebratory" tone of the plot and said Channel 4 had "missed an opportunity" to provide off-screen support such as Internet material linking to safe sex sites, or fact sheets.

The watchdog said it had "concerns about the celebratory tone of the first episode, which left little room for any questions to be raised in viewers' minds about the rights and wrongs of the illegal, under-age relationship".

It said: "A significant number of viewers clearly found this offensive."

Viewers shocked

It said the decision to include three explicit sex scenes in the first show had also shocked many viewers.

The ITC ruled that the wording of the pre-transmission warning about the show's content, which referred to "sex with a capital S", was "less than satisfactory".

Channel 4 had submitted that the age of its 15-year-old character was essential to the plot and that the sex scenes were no more graphic than heterosexual scenes that have been screened on television.

The ITC agreed that the show came within Channel 4's remit.

It praised the series as being of high quality with "a witty script and attractive score".