Sister Jesme was in her twenties and new to convent life when she found herself alone in a room with a priest.

Key points: Some Indian nuns have complained about sexual abuse at the hands of clergy

Some Indian nuns have complained about sexual abuse at the hands of clergy Bishop Franco Mulakkal is on trial in Kerala for repeatedly raping a nun

Bishop Franco Mulakkal is on trial in Kerala for repeatedly raping a nun One sister is risking expulsion from her convent by speaking out against abuse

He told her to undress, then he did the same.

She was so shocked she did not know what to do, so she complied. She had never seen a naked man before.

"I was forced to strip off my clothes by the priest who I thought was a very holy priest."

Later, she was approached by a senior nun who asked her to engage in sexual acts.

"I thought that perhaps if I submit to her, she will be OK," Sister Jesme said.

"So that happened. Other nuns, in a way, were encouraging me to submit to whatever she did. It was a homosexual-type thing."

It took Sister Jesme another 20 years in a religious order before she felt she could speak out about what happened.

"That vow of obedience is the most terrible hammer used on nuns. It is becoming the most important evil inside the convents," she said.

"Nuns are forced to be the slaves of priests. And if it's a bishop? No way to escape."

Nuns isolated in convent after act of defiance

More and more nuns in India are coming forward about sexual abuse at the hands of their clergy. ( ABC News: Siobhan Heanue )

Sister Jesme is one of an increasing number of Indian nuns coming forward about sexual abuse at the hands of senior clergy.

The Catholic Church in India is only just beginning to deal with the kinds of sexual abuse scandals that have rocked the Church elsewhere.

A bishop in the state of Kerala has been accused of raping a nun and other nuns have come forward with similar complaints.

But they say the Church hierarchy is in denial and they have faced reprisals for speaking out.

Bishop Franco Mulakkal worked in the state of Kerala, India's Catholic heartland.

Bishop Franco Mulakkal (second from right), has been charged with raping and sodomising a nun, but remains free on bail. ( Reuters: Sivaram V )

He has been charged with raping and sodomising a nun 13 times over four years.

The nun cannot be identified for legal reasons.

Bishop Franco was shifted out of the state to another diocese and remains free on bail.

Media attention arrived when a handful of nuns spoke publicly in support of the sister who was allegedly raped.

They held a small protest in front of local media but have been kept isolated inside the convent ever since their act of defiance.

The price of speaking up

A nun who refuses to stay silent is Sister Lucy Kalapura, also from Kerala.

Sister Lucy is fighting in court to stay in her convent, after speaking out in support of a nun allegedly raped by a bishop. ( ABC News: Siobhan Heanue )

She said she believes and supports the nun at the centre of the rape case because she experienced similar sexual harassment as a young nun.

"Slowly, priests take the opportunity to take our feelings, our emotions, to please them. They will take that opportunity to touch here and there," she said.

"I experienced that two or three times."

Now 53 years old, Sister Lucy has been threatened with expulsion from her convent for "violating the lifestyle" expected of a nun.

Not only did her superiors take issue with her speaking out, but they have accused her of violating the vows of poverty and obedience by driving a car and using a mobile phone.

Sister Lucy got her driver licence a year ago and took out a loan to buy a small car.

She said being mobile allows her to visit the poor and the sick in her area, some of whom no one else has bothered to befriend.

Sister Lucy's superiors took issue with her speaking out, and now she has been accused of violating the vows of poverty and obedience. ( ABC News: Siobhan Heanue )

"Freedom is love," she said.

Sister Lucy said there is a man suffering from the disfiguring elephantiasis disease who has been shunned by the community, but she drives to his home to see him.

Having lived her whole adult life in the convent, she is terrified of the lonely life she will suffer if she is expelled.

"Throwing me out? It will be horrible and terrible and painful," she said.

Sister Lucy said Church authorities don't want to accept that nuns have rights.

"It is said that nuns are the heart of the church, but they have no power in the church," she said.

'All the blame is upon the women'

The nuns face an extra hurdle in their fight for justice in the state of Kerala.

Attitudes around sexuality are conservative in Kerala, where sisters have been blamed for being complicit in their own abuse. ( ABC News: Siobhan Heanue )

Attitudes around sexuality are very conservative and women are often discriminated against.

The sisters have even been blamed for being complicit in their own sexual abuse.

"If something happens, all the blame is upon the women," Sister Jesme said.

"Maybe it's doubled inside the convent because all the nuns are meant to be very obedient and holy."

Sister Jesme spends her days worshipping privately in her small apartment and said she will never go to mass again unless there is change.

"Let them speak out, let people speak out [about] what is happening and then let us open the window and doors and let the fresh air come in."

Sister Lucy has taken her fight against the Church to India's civil courts and is hoping that system will prevent her from being thrown out of the religious order she loves.

She wrote a letter to the Pope explaining her predicament but received no response.

She hopes the Pope will intervene to end sexual abuse against nuns in one of the Church's most devout strongholds.

"Jesus said what is right is right always, what is truth is truth always, nobody can hide it," she said.