GENEVA - A group of U.N. human rights experts have expressed alarm after Meriam Ibrahim, a Christian mother was sentenced to death and 100 lashes for marrying a Christian man and for refusing to renounce her faith.

The trial of the mother who is pregnant with her second child did not comply with basic fair trial and due process guarantees, said the experts.

"This outrageous conviction must be overturned and Ms. Ibrahim must be immediately released," urged the U.N. experts in a statement Monday.

They also called on the Sudanese government to repeal all legislation that discriminates on the grounds of gender or religion.

"Choosing and/or changing one's religion is not a crime at all; on the contrary, it is a basic human right," said the experts.

They said Sudan should include the protection of the religious identity of minority groups and they urged mainly-Muslim northeast African country to comprehensively its justice system in compliance with international standards.

The U.N. experts noted that capital or corporal punishment can never be justified in the name of religion.

They condemned all "violence that would impair the right to have or adopt a religion, including the use of threat of physical force or penal sanctions to compel believers or non-believers to renounce their religion or to convert."

Aged 27, Ibrahim, was born to a Muslim father and a Christian mother.

She was arrested in 2013 on the grounds of adultery by the Sudanese authorities for being viewed as a Muslim woman cohabitating with a Christian man, whom she married in 2012.

The U.N. human rights experts cited the right to marry and found a family is a fundamental human right of both women and men.

Furthermore they said prosecution for adultery is contrary to international law as "the criminalization of sexual relations between consenting adults is a violation of their right to privacy under international human rights law," said the experts.

In February 2014, an additional charge was brought against her for the crime of apostasy, or publicly renouncing Islam - a faith she never professed.

Ibrahim was given until her next hearing to convert to Islam.

On May 15, the Public Order Court in El Haj Yousif Khartoum confirmed her death sentence for apostasy after she refused to renounce her faith.

The Sudanese mother is currently detained at Omdurman's Women Prison near Khartoum in harsh conditions with her 20 month-old son and will give birth to her second child in the coming month.

'RIGHT TO FREEDOM OF RELIGION'

The UN experts expressed serious concern that "Ms. Ibrahim was convicted for exercising her right to freedom of religion and belief.

"According to international law the death penalty may only be imposed for 'the most serious crimes,' if at all.

They further emphasized the right of every person to "adopt, change or retain a religion of one's choice, and to manifest their religion in practice, observance and worship, as well as the right not to be subject to discrimination or coercion on religious grounds."

Sudan's population is predominantly Muslim, but there are Christian minority communities particularly in the southern region which borders South Sudan.

"The imposition and enforcement of the death penalty on pregnant women or recent mothers is inherently cruel and leads to a violation of the absolute prohibition of torture and other cruel, inhuman or degrading treatment or punishment," said the experts.

The U.N. experts noted, 'There is a pressing need to address the pattern of discrimination, abuse and torture as well as the subjugation and denigration of women in the country.

"We urge the Government of Sudan to put an end to these grave violations of women's human rights," they said.

The experts: Ms. Rashida Manjoo, UN Special Rapporteur on violence against women, its causes and consequences; Mr. Mashood Baderin, UN Independent Expert on the situation of human rights in the Sudan; Mr. Christof Heyns, UN Special Rapporteur on extrajudicial, summary or arbitrary executions; Ms. Gabriela Knaul, UN Special Rapporteur on the independence of judges and lawyers; Mr. Heiner Bielefeldt, UN Special Rapporteur on freedom of religion or belief; Mr. Juan Méndez, UN Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment; Ms. Frances Raday, Chairperson-Rapporteur of the UN Working Group on the issue of discrimination against women in law and in practice; Ms. Rita Izsák, UN Special Rapporteur on minority issues; Mr. Mads Andenas, Chair-Rapporteur of the UN Working Group on Arbitrary Detention.