Robert Kyagulanyi, a Ugandan pop star-turned-opposition politician, has alleged that security officers beat him and squeezed his genitals until he lost consciousness while in detention, in his first public statement since his arrest last month.

Kyagulanyi, whose stage name is Bobi Wine, was held on August 14 and charged with treason over his alleged role in the stoning of President Yoweri Museveni's car during a by-election campaign.

The 36-year-old, whose case has drawn international attention, was released on bail nearly two weeks later. But Kyagulanyi was rearrested last week while trying to leave the country to seek medical treatment in the United States. He was subsequently allowed to depart.

Ugandan authorities have rejected the accusations of torture but said they will investigate them.

In a lengthy statement posted on Facebook on Monday, Kyagulanyi wrote that he wanted to "set the record straight".

"They wrapped me in a thick piece of cloth and bundled me into a vehicle. Those guys did to me unspeakable things in that vehicle! They pulled my manhood and squeezed my testicles while punching me with objects I didn't see," Kyagulanyi alleged.

"They beat me, punched me, and kicked me with their boots. No part of my body was spared. They hit my eyes, mouth and nose. They hit my elbows and my knees," he added.

"By the time I became conscious again, I was somewhere in a small room with a small window. My legs were tied together with my hands with very tight cuffs. I was bleeding from the nose and ears. I was in great pain. The cloth they had tied me in was red-soaked in blood. My whole body was swollen."

Kyagulanyi also wrote that a radiologist told him "how one of my kidneys and back had been damaged during the assault. I was however not given any written medical report by the military" (Aljazeera)