BISHKEK -- Kyrgyzstan's Supreme Court has upheld the convictions of three opposition politicians in a high-profile case but reduced their prison sentences.

Under the June 7 decision, the prison terms of Bektur Asanov and Kubanychbek Kadyrov were shortened from 12 years to eight years, and Ernest Karybekov's 20-year prison term was cut by six years.

The three were arrested in March 2016 after an audio recording that featured voices similar to theirs discussing ways to overthrow the government circulated on the Internet.

Asanov told RFE/RL before his arrest that the tapes had been doctored and that they were posted online in "an attempt to blackmail the opposition."

The trio were charged with plotting to overthrow the government, and were convicted and sentenced in April 2017.

In February, the Bishkek City Court upheld the sentences and the three were transferred from the State Committee for National Security's (UKMK) detention center to a prison near Bishkek.