Elderly migrants who for decades were refused Australian citizenship on political grounds are calling for official acknowledgement of their mistreatment from the federal government.

Hundreds of migrants who came to Australia under a postwar settlement scheme were denied naturalisation for decades without being given a reason, an SBS investigation has found.

Declassified immigration and Asio files showed the migrants were recorded as national security risks because of suspected or confirmed associations with the Communist party of Australia or some migrant community groups.

The national spy agency kept hundreds of migrants and their communities under surveillance for decades and maintained a secret list of thousands earmarked for potential internment and other restrictions because of their political beliefs, the investigation found.

Most of those SBS spoke to had joined political migrant groups, had links to the Communist party of Australia, visited clubs with connections to communist countries, or were involved in trade unions.

The measures were taken from the 1950s to the 70s. The investigation found information on individuals in Australia was traded with foreign intelligence agencies, including the rightwing Greek government in the aftermath of that country’s bitter civil war.

The migrants told SBS they suffered severe consequences because of their residency status – including being targeted for deportation, criminal charges, restricted travel to their homelands and social exclusion.

They want acknowledgement they were wrongly treated and a formal apology from the federal government.

The former high court judge Michael Kirby, who has just completed a UN investigation into human rights in North Korea, said Australia needed to “acknowledge that wrongs were done and to have it expressed in our national parliament”.