A chain of fast food restaurants has defended a radio commercial that makes light of detained refugees who sew their lips together in protest at their incarceration. Nando's, a South African-owned firm that prides itself on its Portuguese-style chilli chicken, says it has a history of producing 'provocative and challenging' advertisements. But the advertising industry, and some listeners, say the campaign is in poor taste. The 15-second ad, being broadcast on the radio this week, boasts that asylum seekers at the Woomera detention centre in South Australia have 'decided to unsew their lips after hearing that with every Nando's quarter chicken combo, Nando's are giving away an extra quarter chicken free'. Lip sewing - usually involving one or two stitches - is one of the more disturbing forms of protest used by mainly Middle Eastern and Afghan asylum seekers in Australia's six detention camps. There have also been hunger strikes, demonstrations and riots. Carlos Antonius, Nando's national marketing manager, said: 'It may be perceived to be in bad taste - but we don't think we're belittling them at all. 'We think if it gives them coverage and it also gives us coverage - that's a good thing.' He said the advert had received compliments as well as complaints. But Chris Thomas, of the Advertising Federation of Australia, said: 'We believe that advertising does need to be bold and innovative, even cheeky to cut through to consumers, but it also needs to be able to gauge the temperature of the community in regards to social issues. We feel that this advertisement clearly oversteps the line and we're actually quite appalled by it.' It is not the first time that Nando's, which opened its first outlet in Australia in 1997, has sparked controversy. At the height of anti-immigration politician Pauline Hanson's popularity, the company came up with a poster that featured black, white and brown chickens and the caption, 'We're all the same on the inside, Pauline'.