Video footage appearing to show migrants at the reception centre on Lampedusa standing naked in the open air while waiting to be sprayed for scabies has provoked a storm of protest in Italy.

Broadcast by the Rai 2 television channel on Monday night, the pictures appeared to show a practice that was labelled "unworthy of a civilised country" by Laura Boldrini, the speaker of the lower house of parliament. Coming barely two months after hundreds of people died in two separate disasters in the Mediterranean, the footage provoked renewed criticism of Italy's creaking reception system for asylum seekers and refugees.

"Italy should be ashamed," Giusi Nicolini, mayor of Lampedusa, told Rai 2 television. "It [the reception system] has to change. This is not what we were expecting to see just two months after the shipwrecks which prompted weeping, tears, commitments and promises."

In the footage, which appeared to have been shot on a mobile phone, at least two men at the reception centre are shown standing with no clothes on, while others are undressing.

It was unclear whether the men had been obliged to remove their clothes. Italy's interior minister, Angelino Alfano, said a detailed report into the images would be ready within 24 hours and that "whoever erred will pay".

A spokesperson for Amnesty International was quoted by the Ansa news agency as saying: "Migrants arriving in Italy, as in any other country, need an appropriate medical exam in their own interests and in the interests of the country receiving them.

"Nonetheless, migrants' privacy and dignity must be respected and no migrant should be asked – let alone forced – to take their clothes off in public."

Boldrini, a former spokeswoman in Italy for the UN refugee agency UNHCR, said in a statement: "These images cannot leave us indifferent. All the more so because they come after the tragic shipwrecks of October and after the commitments that Italy made in terms of reception [of asylum seekers and migrants]. This kind of degrading treatment discredits the image of our country and demands dignified responses."