A court in Kerala on Friday acquitted Roman Catholic Bishop Franco Mulakkal of the charges of raping a nun in a convent in the southern state, triggering emotional reactions from nuns who support the survivor, while the jubilant priest urged followers to "praise the lord and be happy".

As the prosecution failed to produce evidence against the accused, G Gopakumar, judge of the Additional District and Sessions Court I, Kottayam, acquitted the Bishop.

Mulakkal, 57, was accused of raping the nun multiple times during his visit to a convent in this district between 2014 and 2016 when he was the Bishop of the Jalandhar diocese of the Roman Catholic church. The survivor is a member of the Missionaries of Jesus, a diocesan congregation under the Jalandhar Diocese.

A visibly relieved and emotional Mulakkal, who arrived in the court to hear the verdict, burst into tears, hugged his followers and lawyers, sharing his joy over the verdict.

"Daivathinu Sthuthi (praise the Lord)," Mulakkal said when reporters repeatedly sought his reaction.

Some of his followers were even seen crying out of joy after hearing the acquittal of the bishop.

In a brief Malayalam statement issued soon after the verdict, the Jalandhar diocese thanked those who believed in the innocence of the Bishop till date and provided him with the necessary legal assistance.

A group of nuns of Kuravilangad Convent here, who have been standing with the survivor in her fight, were on the verge of tears when they said they were yet to believe such a verdict came out from the court and they did not know what has happened.

The survivor and her supporters stay in the Kuravilangad convent in this south Kerala district.

Sister Anupama, who was the face of the nun's years-long fight for justice, said they would surely challenge the verdict in the higher court and take forward the fight of their hapless colleague.

"We will continue our stay in the convent and take forward our fight till our sister gets justice. Police and prosecution showed justice to us but we did not get the expected justice from the judiciary," the teary-eyed nun told reporters.

Noted criminal lawyer B Raman Pillai, who led the Bishop's legal team, said they have got the right to file the appeal against the verdict. "Even if they go for appeal, there is no tension as prosecution charges against the Bishop are false", Pillai told PTI.

Explaining the factors that contributed to the verdict in his party's favour, the lawyer said the prosecution case was very weak, investigation was very poor and statements of most of the witnesses came in favour of the accused because they were telling the truth.

He claimed that the defence team could expose in the court the manipulation of a most important document by the investigation team.

Investigators, lawyers and social activists who stood with the nun in her fight against Mulakkal expressed shock over the verdict, saying it was totally unexpected.

Terming the verdict as "very, very unfortunate" and "unnatural'', senior IPS officer S Harishankar, who had led the special investigation team in the rape case, said 100 per cent conviction was expected in the case and the verdict would be an "astonishment" for the entire legal system of the country.

In the case, the survivor was a nun and the assailant was a person who was powerful enough to decide whether she should continue to live or die.

"The argument that the woman should have reacted at the time of molestation is unacceptable. An appeal will be filed in the higher court challenging this verdict. The state police chief already gave instructions in this regard and an appeal will be filed as soon as we get a copy of the verdict," he told reporters.

Even the supreme court made it clear multiple times that the victim's statement, if it is consistent and not having massive contradictions, is a satisfactory piece of evidence for conviction, he said, adding that it would give a wrong message to society and those suffering similar assaults silently.

Public prosecutor Jithesh J Babu said it was a single-line judgment and could avail the details only after getting the copy of the verdict.

"We do not know what has happened. Thirty-nine witnesses have given their statements supporting the prosecution. No one has turned hostile. As many as 122 documents had been submitted and there was ample evidence. There was no lapse in anything," he said.

He also said the verdict would be challenged in the higher court and the decision would be taken after consulting with the government and the investigators.

A visibly relieved and emotional Mulakkal, who arrived in the court to hear the verdict, burst into tears, hugged his followers and lawyers, sharing his joy over the verdict.

"Only the trees that bear fruits are stoned. I am just proud of that. Praise the Lord," the bishop said.

He said the verdict has proved that there is god and the justice of heaven was delivered on earth.

"Those who respect the truth were with me," said Mulakkal, the first Indian Bishop arrested in connection with a rape case.

Rushing from the court immediately after the verdict, the Bishop visited a retreat centre here and led a holy mass praising the Almighty.

Activist-nun Sister Lucy Kalappura, who took part in the survivor's fight for justice and was expelled from her congregation recently, said the verdict was regrettable and expressed hope that justice would be prevail at any cost in the higher court.

In her complaint to the police in June, 2018, the nun had alleged that she was subjected to sexual abuse by Franco Mulakkal between 2014 and 2016.

The Special Investigation Team, which probed the case, arrested the Bishop in September 2018 and charged him with wrongful confinement, rape, unnatural sex and criminal intimidation.

Trial in the case, which started in November 2019, had concluded on January 10. The court had restrained the print and electronic media from publishing any matter relating to the trial in the case without its permission.