Kigali (AFP) - A popular Rwandan singer whose music was banned by the ruling regime "committed suicide" in custody, police announced Monday, three days after he was caught trying to flee the country.

Kizito Mihigo, a survivor of the Rwandan genocide whose songs angered the government of strongman President Paul Kagame, was found dead in a police cell in the capital Kigali around 5am (0200 GMT).

Mihigo, who was sentenced to 10 years' jail in 2015 for conspiracy against the government but later released on pardon, was captured trying to cross the border in Rwanda's south.

Police spokesperson John Bosco Kabera said he was visited by family members and his lawyer during his detention.

"Investigations have begun to ascertain why he committed suicide," he said.

Mihigo fell foul of the ruling RPF in 2013 after composing songs that questioned the government's tight control of the legacy of the 1994 tragedy.

His music, once popular by ruling elites, was swiftly banned.

Two years later he was accused of terrorism and raising support for an opposition political movement and sentenced to 10 years in prison.

His lawyers said prosecutors had little evidence to jail him. He was released on presidental pardon in September 2018.

Mihigo is not the first figure to die in mysterious circumstances under police custody in Rwanda.

Last year, a former director-general in Kagame's office was found dead in a military jail after being sentenced to 10 years for corruption.

In 2015, Kagame's personal doctor, Emmanuel Gasakure, was shot dead in custody by police.

Kagame, who has been in power since 1994, has been accused of ruling with an iron fist, clamping down on all forms of dissent and jailing or exiling opposition politicians.

Human Rights Watch, among other rights watchdogs, has accused Kagame's regime summary executions, unlawful arrest and detention and torture in custody.