(Dec. 10) — Amnesty International accused Iranian authorities Thursday of perpetrating the worst human rights abuses in more than 20 years as they try to tamp down broad dissent following President Mahmoud Ahmadinejad’s contested re-election in June. The charge comes amid allegations that some of the regime’s top officials, including one who supervised those elections, have repeatedly published plagiarized academic papers.

In its 80-page report, Amnesty contended that “the most severe period of repression since the end of the revolutionary period” has left many Iranians “living with a heightened fear of arbitrary arrest and detention, torture, unfair trial and even execution.”

The London-based human rights organization said that more than 4,000 people were imprisoned during the protests that followed the June 12 elections. The unrest has resurfaced repeatedly since the summer, most recently during several days of violent clashes this week around Tehran University.

The organization said that many of those detained since June have been subjected to show trials without proper legal representation or even clear charges. Amnesty said at least 112 people have been executed since the elections, far more than the regime’s usual pace of capital punishment. Though most of those executed were convicted on charges of drug trafficking or armed opposition to the state, Amnesty contends the spate of hangings was meant to send “a chilling message to dissidents.”

Detainees were also subjected to physical abuse in detention, Amnesty said, especially rape. When first reports of such practices surfaced, particularly at Kahrizak prison on the outskirts of Tehran, the authorities ordered the prison closed and mandated two separate investigations. But Amnesty said neither investigative committee has released public findings and that members had dismissed the allegations, “reinforcing the climate of impunity enjoyed by security forces, prison guards, police and Basij militia.”

Another damning look at the character of the Iranian regime surfaced this week in a less likely venue: the prestigious scientific journal Nature. In the second of a series of investigations into charges of academic plagiarism at the top of the regime, journalist Declan Butler detailed evidence that scientific papers submitted by the minister of transport, Hamid Behbahani, and the head of Iran’s largest long-distance university, Hassan Ziari, included passages lifted from previously published articles.

Butler had earlier uncovered evidence of plagiarism by Iranian Science Minister Kamran Daneshjou, who supervised June’s contested Iranian presidential elections as an interior ministry official. According to Nature, a parliamentary commission created in October to look into the plagiarism charges “effectively cleared Daneshjou after his co-author … took responsibility for the papers’ contents in the Iranian media.” The foreign journals that published three of the four contested papers Daneshjou co-authored have retracted them.