CAPE TOWN: Archbishop Desmond Tutu, a hero of the struggle against apartheid in South Africa, will be laid to rest on Saturday in an official state funeral in St George's Cathedral, Cape Town, where for years he preached against racial injustice.

President Cyril Ramaphosa is expected to deliver the main eulogy for Tutu, whose death on Sunday aged 90 triggered an outpouring of tributes from around the world.

Tutu, awarded the Nobel Peace prize in 1984 for his non-violent opposition to white minority rule, was known for his infectious laugh and easy-going manner but they belied a steely resolve to fight for the downtrodden during the darkest hours of apartheid and beyond into the 21st century.

Widely revered across South Africa's racial and cultural divides for his moral integrity, Tutu never stopped fighting for his vision of a "Rainbow Nation", in which all races in post-apartheid South Africa could live in harmony.

"Without forgiveness, there's no future," the charismatic cleric once said.

SIMPLE COFFIN

Hundreds of well-wishers queued on Thursday and Friday to pay their last respects to Tutu as he lay in state at the cathedral in a simple, closed pine coffin with rope handles, in accordance with his wishes for a frugal funeral.

As Anglican archbishop of Cape Town, Tutu turned St George's into a refuge for anti-apartheid activists during the turbulent 1980s and 1990s when security forces brutally repressed the mass democratic movement.

His body will be cremated in a private ceremony after Saturday's requiem mass and will then be interred behind the pulpit from where he once denounced bigotry and racial tyranny.

Church bells have tolled daily this week at St George's in honour of the man often described as South Africa's "moral compass". Many would refer to Tutu as "Tata" or father.

"Sometimes strident, often tender, never afraid and seldom without humour, Desmond Tutu's voice will always be the voice of the voiceless," is how long-time friend and former president Nelson Mandela, who died in December 2013, described his friend.