“Police officers came to the door and said ‘All blacks out, all blacks out'," Tupac told me as he recalled how police officers forced him and other black and Asian passengers off a bus in central Athens for an identity-check. After pulling him out of the bus, the police held Tupac, a Guinean registered asylum-seeker, for almost ten hours to check his legal status in Greece. All this happened in early February 2013.

Tupac is one of tens of thousands of people who’ve been stopped, searched and detained by the police under Operation Xenios Zeus - an epic sweep operation to crack down on irregular immigration that began almost a year ago. Whoever gave the operation its title has a twisted sense of humour: Xenios Zeus was the ancient Greek god of hospitality.

While researching police practices under Operation Xenios Zeus, I heard many disturbing accounts of clear targeting by the police on the basis of race or ethnicity during identity checks. The number of people stopped and detained is mind-boggling. In the first seven months, police rounded up almost 85,000 foreigners and took them to police stations to verify their documents. Of these, fewer than 6% were then arrested for unlawful entry and stay in the country. The fact that such a small percentage was actually found to be in Greece unlawfully suggests ethnic profiling and arbitrary deprivation of liberty.

I spoke to dozens of foreigners, including migrants and asylum-seekers with a legal right to be in Greece, who have been repeatedly subjected to these lengthy procedures by the police, both on the street and at police stations. People on their way to work, to the grocery store, or just walking in Athens city centre described being stopped and held by police officers in the street, confined in police buses, and detained in police stations and the Aliens Police Division for hours. The police had no reason to think they were undocumented migrants, except for their physical appearance.

Ethnic profiling is discriminatory and unlawful when groups are systematically targeted solely or mainly on the basis of race or ethnicity. Depriving people of liberty is also unlawful and arbitrary when based on discriminatory grounds such as in Xenios Zeus. It is true that the influx of destitute migrants living on the streets has brought disconcerting change to Greek cities, particularly in Athens. Immigration, as well as concerns about rising crime and urban degradation, have become dominant features of everyday conversations as well as political discourse. With the far-right, anti-immigrant party Golden Dawn gaining in popularity and a wider shift in public sentiment, it’s hard not to see heavy-handed measures like Xenios Zeus as a public-relations response. That’s especially true given that police and government officials say the operation’s been a success, despite the small number of irregular migrants actually apprehended for all that expenditure and effort.

In mid-June, I met high-ranking police and government officials to discuss our findings and recommendations. I was struck by how defensive government officials and parliament members from the ruling New Democracy Party were about the issue. Athanasios Andreoulakos, secretary-general of the public-order ministry, as well as members of the parliamentary committee on public order, denied and rejected our findings outright. In response to our call to publicly reject ethnic profiling and other instances of police abuse, Andreoulakos said the government would “never condemn something that does not exist.” We were also told repeatedly that Greece is historically tolerant with a longstanding tradition of hospitality, that it is a victim of a mass influx of migrants, and that it’s “in the DNA of Greeks not to be racist.”

Our recommendations on training, technical capacity, and guidelines for police officers on how to conduct immigration stops while respecting rights were more attractive to officials. In a meeting with justice minister Antonis Roupakiotis and the ministry's secretary-general Marinos Skandamis, they promised to examine ways to clarify the legal framework governing the procedure. Since we met a few weeks ago, Roupakiotis has been replaced in a government reshuffle amid Greece’s latest political crisis. The wider political instability in the country, and the government's small majority in parliament, mean the personnel could change again. But as long as Operation Xenios Zeus remains in force, violations of rights will continue.

The bottom line is that Greece should not discriminate based on race or ethnicity and should not subject migrants to arbitrary deprivation of liberty and other abusive treatment, irrespective of who is in power. The Greek authorities should revise Greece’s general stop-and-search powers, including for Operation Xenios Zeus, and adopt legal and policy reforms to ensure that all measures to identify irregular migrants fully comply with national and international law prohibiting discrimination. Police officers conducting immigration stops need appropriate training, equipment, and guidance on how to conduct immigration stops without abusing people’s rights. Instead of focusing on discriminatory sweep operations like Xenios Zeus, stigmatising migrants and asylum-seekers, Greece should invest more in stemming the tide of anti-immigrant sentiment in the country. This would also be to show migrants and asylum-seekers the true meaning of Greek hospitality.