Adeline Mukangemana 22-year prison sentences for, among other charges, inciting insurrection.
The trial resumed a month after the two women were released on bail having spent more than a year in jail.
At the seven-hour hearing, the state attorneys focused on contents of audio and video clips as well as documents confiscated from their home and office last September when they were arrested.
The prosecution said the evidence produced in court pointed to their intention to foment insurrection against the government.
Ms Rwigara, a prominent government critic, is also charged with forgery of electoral documents that saw her disqualified from the presidential race in 2017.
“We request that Diane Rwigara be imprisoned for 15 years for inciting insurrection and seven years for forging documents,” prosecutors told the High Court.
But the 37-year-old denied the forgery claims saying they were accusations meant to derail her from challenging President Paul Kagame in the elections.
She also defiantly told the court that she stood by her remarks about the government’s human rights violations and that they reflected her political journey. She said she was calling on Rwandans to “resist fear and speak for our country”.
“When I say that people are being forcefully driven away from their land, I have evidence including articles published by local media. When I mention poverty or lack of access to water and electricity, there are global reports by World Bank and others confirming that,” she told the three-judge bench.
“When I talk about killings and disappearances, there are reports by rights groups,” she said, adding that the charges against her were fabricated.
Her lawyer Pierre Celestin Buhuru told the court that Ms Rwigara had exercised her constitutional right to freedom of expression and wanted to contribute positively to the national discourse, adding that a person should not be held against his or her views.
Mr Buhuru added that allegations against her were only meant to force her out of the presidential race.
The prosecutors also demanded a prison sentence of 22 years for the Rwigara matriarch for inciting insurrection and promoting sectarianism.
Mrs Rwigara is charged along with Tabitha Mugenzi, her sister who resides in Canada, Mr Xaverine Mukangarambe and Mr Jean Paul Turayishimiye both in the US, and Mr Edmund Musheija in Belgium.
But she argued that the recordings produced in court were private conversations among relatives that revealed the pain of the loss of her husband Assinapol Rwigara who died in a car accident in 2015, an account the family questions.
“It is the pain of my husband who contributed to the liberation of this country but he was repaid by constant hounding until he was killed in the circumstances he died,” she said, adding that her request for a probe into the death was turned down by the people behind his death.
The family says their troubles began after the death of the father. They are also battling property auctions as the taxman moves to recover $6.5 million it says it is owed by the family-owned businesses.
The trial on Wednesday was attended by family, friends and diplomats. Among them was Victoire Umuhoza Ingabire, who was granted a presidential pardon in September after serving six years of her 15-year jail sentence, which the Supreme Court handed her for belittling the 1994 Genocide Against the Tutsi, forming an armed group and inciting public revolt.
She had just returned to Rwanda to run for the presidency in 2010 when she was arrested.
Ms Ingabire told The EastAfrican that she hoped the court would not convict the pair for simply expressing their views.
“We are confident that a recent decision to grant them bail shouldn’t be tainted by a harsher sentence. In essence, Diane and her mother expressed their views on what was happening to them as a family and what was happening in the country,” she said.
“We should not be seen as a country which jails people for expressing their views. My hope is that the judges will make a decision that is good for the country,” Ms Ingabire said.
The High Court set the ruling date for December 6.