The family of Robert Kyagulanyi, a Ugandan pop star-turned-opposition legislator, fears for his safety after he was blocked from boarding a flight to the United States and brought to a government hospital where he was detained, his lawyer said.
Kyagulanyi, whose stage name is Bobi Wine, was stopped while trying to board a flight at Entebbe airport on Thursday.
He was reportedly on his way to the US to receive treatment for his injuries from alleged torture, his lawyers said.
Wine's detention at the hospital remains a worry for his family now, said his lawyer Robert Amsterdam.
"When the very doctors who supervised the torture are being asked to opine on his medical condition, there's absolutely no way we or anyone competent would agree to that," said Amsterdam, speaking to Al Jazeera from the British capital, London.
"There's no independent body here. These are doctors connected to Ugandan special forces. We are not going to let them near him. We know that they injected him with God knows what when he was being he was tortured before.
"Burn marks are showing up on his body. We want to get him out. We want to get him to an independent clinic for assessment."
Kyagulanyi's Ugandan lawyer Nicholas Opiyo said that police "violently abducted" the politician and put him in a police ambulance at the airport.
"The Uganda Police have violently blocked Bobi Wine from travelling outside of the country in spite of the court declining to do so when being released on bail earlier in the week," said Opiyo. "This is absurd, to say the least."
Kyagulanyi's wife, Barbara, said in a Facebook post that security forces "manhandled" her husband, who "groaned in pain" as he shouted for help.
Police did not immediately respond to a request for comment.
The 36-year-old opposition leader was freed on bail on Monday but faced no travel restrictions after he and more than 30 other legislators were arrested over an incident in which the president's motorcade was pelted with stones and Kyagulanyi's driver was shot dead.
A lawyer for Kyagulanyi called the charge false.
Fresh protests across Kampala took place on Friday with Kyagulanyi's supporters burning tires and setting up barricades across streets.
"There's a huge military and police presence at this [government] hospital," said Al Jazeera's Catherine Soi, reporting from Nairobi, in neighbouring Kenya.
"Kyagulanyi's personal doctors recommended that he needs further treatment, but police say they do not have that instruction," she said.
The police action has escalated a political dispute between the government of longtime President Yoweri Museveni and a youthful generation that fears he intends to rule for life after 32 years in power.
Kyagulanyi emerged as a powerful opposition voice among youth frustrated by Museveni, especially after the constitution was changed last year to remove an age limit on the presidency.
The singer won a parliament seat last year without the backing of a political party.
On Thursday, another legislator, Francis Zaake, was barred from boarding a plane to India, with authorities saying he was a suspect in a criminal case.
Government spokesperson Ofwono Opondo said on Twitter that Zaake, who has not been charged with a crime, escaped police custody "and should be arrested at the earliest".
After the outcry over Kyagulanyi's treatment at the airport, Opondo said both he and Zaake can travel "after government doctors have examined them to ascertain their medical conditions".
Both men had been hospitalised with serious injuries they said they sustained at the hands of security forces during detention.
Kyagulanyi's lawyer Amsterdam said the "authorities were not legally justified" in barring his client from leaving the country.
"We've seen this before in other countries where there has been torture, governments are very concerned about that information getting out," he told Al Jazeera.
The speaker of Uganda's parliament, Rebecca Kadaga, in a letter to Museveni this week described Zaake as "gravely ill" and said Kyagulanyi "has visible signs of torture and beatings".
The government has denied the allegations of torture.