Former Liberian President Charles Taylor appears in court at the Special Court for Sierra Leone in Leidschendam, western Netherlands.

The Hague - Prosecutors called for a stiffer sentence for former Liberian president Charles Taylor on Tuesday, telling war crimes judges in the Hague he played a direct role in crimes against humanity during the civil war in Sierra Leone.

Meanwhile, Taylor's defence, which wants his conviction overturned, wrote in filings to the court hearing both appeals that the conviction was “plagued with internal inconsistencies, misstatements of evidence and conflicting findings”.

Taylor, 64, was sentenced to 50 years last year after being found guilty of aiding and abetting war crimes and crimes against humanity during the 11-year war in neighbouring Sierra Leone, in which an estimated 50,000 people had died by 2002.

He was found not guilty of either ordering or planning the atrocities.

But prosecutors told Tuesday's appeal hearing that Taylor's involvement went beyond helping the commission of crimes, saying that he should be convicted for the direct commission of war crimes and for instigating them.

They also asked for his prison sentence be raised to 80 years, which they had originally demanded in May 2012.

“He was aware of the crimes (being committed in Sierra Leone) through his own sources, as president of Liberia, and through media reports,” Brenda Hollis, head prosecutor at the Special Court for Sierra Leone, said at the hearing on Tuesday.

Dressed in a dark suit and a bright red tie, Taylor leaned forward with his hands clasped together, listening attentively in a windowless former basketball court in a suburb of The Hague.

Prosecutors put their appeal case in the morning, with the defence team taking over in the afternoon.

Over more than a decade of brutal conflict, Revolutionary United Front rebels murdered, raped and mutilated their way across Sierra Leone.

In return for providing arms and ammunition for the conflict, Taylor received “blood diamonds”, as the stones from Sierra Leone's conflict zones were known, including a 45-carat diamond and two 25-carat diamonds.

The prosecution argues the relationship was even closer, and that Taylor was in direct charge of the rebels as they terrorised a civilian population.

“What was Charles Taylor's reaction to all these reports of atrocities?” asked Nicholas Koumjian, a member of the prosecution. “To send more ammunition.”

His actions were evidence of his direct involvement in the crimes, Koumjian added. When Taylor instructed Sam Bockarie, an RUF commander, to make the attack on the Sierra Leonean capital Freetown “fearful”, he had known that brutality might ensue, Koumjian said.

“He was saying this to the RUF, not to a boy scouts' troop,” Koumjian said. “Putting people's heads on sticks. That's what 'make it fearful' meant.”

The appeals hearing will continue on Wednesday. - Reuters