The mobile phone of the victim, a key evidence in the case, is also yet to be found, police said.
The probe team would have taken the next step in the investigation had they got "totally believable statements" in the case against Jalandhar Bishop Franco Mulakkal, a police official said, requesting anonymity.
The police cannot act merely on the basis of doubt regarding the incident that occurred four years ago, Sankar told PTI when asked about the alleged delay in the investigation into the case, an officer said, requesting anonymity.
"They will act only after they are fully convinced... We are trying our best (to gather evidence)," he said.
The mobile phone of the nun, which was supposed to be the source of evidence against the accused, is to be found, Sankar said.
"We will be able to recover the data-- like any sexually explicit messages even if they were deleted---if we get the mobile phone," he said.
Police said they were not having "a fully transparent interaction" with the victim.
However, Mulakkal has claimed that he is innocent and said the truth would come out in the investigation.
Clergymen supporting Mulakkal had said that the nun had filed the complaint against him after a priest, also an official of the Jalandhar diocese, filed one against her relatives for allegedly threatening the bishop.
In his complaint, the priest has alleged that the nun's relatives threatened to kill Mulakkal after he ordered a probe against her on the basis of the complaint received by the Mother Superior of her congregation.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)