The company released an independent report showing that East German prisoners, among them many political dissidents, were involved in the manufacture of goods supplied to IKEA between 25 and 30 years ago.

The report concluded that IKEA managers were aware of the possibility that prisoners would be used in the manufacture of its products and took some measures to prevent this, but they were insufficient.

“We deeply regret that this could happen,” Jeanette Skjelmose, an IKEA manager, said in a statement. “The use of political prisoners for manufacturing was at no point accepted by IKEA.”

But she added that “at the time we didn’t have the well-developed control system that we have today and we clearly did too little to prevent such production methods.”

IKEA asked auditors Ernst & Young in June to look into allegations aired earlier this year by a Swedish television documentary, but first raised by a human rights group in 1982.

Rainer Wagner, chairman of the victims’ group UOKG, said IKEA was just one of many companies that benefited from the use of forced prison labor in East Germany from the 1960s to 1980s.

“IKEA is only the tip of the iceberg,” he told The Associated Press in an interview earlier this week.

Wagner said he hoped that IKEA and others would consider compensating former prisoners, many of whom carry psychological and physical scars from arduous labor they were forced to do.

“IKEA has taken the lead on this, for which we are very grateful,” he told a news conference in Berlin, where the findings of the report were presented.

According to historians, forced labor was a widespread phenomenon in East Germany, which desperately needed hard Western currency to support its planned economy. The prison labor is estimated to have cost a tenth of what it would have cost in the west.

Some 23 years after the fall of the Berlin Wall, experts are still trying to understand the full extent of the regime’s exploitation of its people.

Alexander Arnold, who was imprisoned in Naumburg in the early 1980s, said prisoners who failed to meet a quota were punished.

“If one delivered less than 80 percent of the expected standard, one was accused of sabotage,” he said.

Anita Gossler, a campaigner and former prisoner, said inmates of East Germany’s notorious Hoheneck prison for women were forced to sew bedclothes destined for foreign companies.

“There were three shifts each day,” she said. “You couldn’t refuse. If you did you were locked in a dark cell with bread and soup for at least three days.” Until 1980 prisoners also risked being sent to the ‘water room,’ where they had to stand knee-deep in cold water for hours.

Gossler said one inmate once managed to hide a note in a bed cover that was later discovered by an IKEA customer in the west — a rare piece of evidence of forced labor at the time.

Peter Betzel, the head of IKEA Germany, said the company would continue to support efforts to investigate the use of prisoners in East Germany.

Today, he said, “we can exclude with almost 100 percent certainty that such things as happened in East Germany happen elsewhere.”

IKEA has over 300 stores worldwide, racking up sales of €26 billion ($33.14 billion) last year, according to its website.

The company has been embroiled in controversy in the past. A book published last year claimed IKEA founder Ingvar Kamprad joined the Swedish Nazi party in 1943 when he was 17 and remained in contact with Nazi sympathizers until at least 1950.

The allegations by respected Swedish author and journalist Elisabeth Asbrink went beyond what Kamprad had previously acknowledged in a 1988 book about his life. At the time, he asked for forgiveness for his youthful “stupidity.”