A UN-backed Sierra Leone court has convicted former Liberian president Charles Taylor of war crimes.

He is the first African head of state to be found guilty by an international tribunal.

Taylor, 64, was charged with murder, rape, conscripting child soldiers and sexual slavery during intertwined wars in Liberia and Sierra Leone, in which more than 50,000 people were killed.

The court found him guilty of only some of the charges. He will be sentenced on 30 May.

The court, based in Leidschendam outside The Hague, delivered its judgment this morning.

Taylor was accused of helping Sierra Leone's Revolutionary United Front (RUF) rebels wage a terror campaign during a civil war that claimed 120,000 lives between 1991 and 2001.

The trial, which saw British supermodel Naomi Campbell testify that she had received diamonds from the flamboyant Taylor, ended in March 2011.

"There is a wave of anticipation ahead of the judgment," Alpha Sesay, legal officer at the Open Society's Justice Initiative in The Hague, said earlier.

"Not only in The Hague, but in Sierra Leone and in Liberia as well - by victims of the conflict, by the countries' governments and by Taylor's supporters," he said, adding: "Finally, it will be good to know."

Prosecutors alleged that the RUF paid Taylor with illegally mined so-called blood diamonds worth millions, stuffed into mayonnaise jars.

During the trial, prosecutor Brenda Hollis told the court: "Charles Taylor created, armed, supported and controlled the RUF in a 10-year campaign of terror against the civil population of Sierra Leone."

As president of neighbouring Liberia, he acted as "chief, father and godfather to his proxy rebel forces in Sierra Leone," prosecutors added.

The former warlord pleaded not guilty to 11 counts, dismissing the allegations as "lies" and claiming to be the victim of a plot by "powerful countries."

During Taylor's trial, which began on 4 June 2007, some 94 witnesses took to the stand for the prosecution and 21 for the defence.

Taylor himself testified for 81 hours.

Ms Campbell and actress Mia Farrow gave headline-grabbing evidence in August 2010 about a gift of "dirty" diamonds Taylor gave to Ms Campbell at a charity dinner hosted by then South African president Nelson Mandela in 1997.

Judges also heard gruesome testimony from victims of the Sierra Leone conflict, including a witness who said he pleaded with RUF rebels to cut off his remaining hand so they would spare his toddler son.

Others said Taylor's fighters strung human intestines across roads, removed foetuses from women's wombs and practised cannibalism, while children younger than 15 were enlisted to fight.

One witness said he was present when the Liberian leader ate human liver.

During his own testimony, which began in July 2009, Taylor called the trial a "sham" and denied allegations he ever ate human flesh.

Nigerian authorities arrested Taylor in March 2006 when he tried to flee from exile in Nigeria after stepping down as Liberian president three years earlier in a negotiated end to a civil war in his own country.

He was transferred to the SCSL in Freetown, but in June 2006 a UN Security Council resolution cleared the way for him to be transferred to The Hague, saying his presence in west Africa was an "impediment to stability and a threat to the peace."

The court, set up jointly by the Sierra Leone government and the United Nations, has already convicted eight Sierra Leoneans of war crimes and jailed them for between 15 and 52 years after trials in Freetown.

Charles Taylor's conviction represents a "landmark" in the battle to hold accountable all perpetrators of atrocities, said EU foreign policy chief Catherine Ashton.

"The judgment delivered today by the Special Court for Sierra Leone ... constitutes a major achievement for this Court and represents a landmark decision in the fight against impunity," Ms Ashton said in a statement.