The Indian-origin nun is thought to be the first from the Missionaries of Charity order to be imprisoned
A nun in Sri Lanka is to appear in court in connection with the failure to disclose an underage pregnancy at a mother and baby shelter.
Sister Mary Eliza, superior nun at a Missionaries of Charity convent near Colombo, was given bail on Monday.
Police raided the convent last week after child welfare officers said they suspected her of involvement in child-trafficking, claims the church denies.
During the raid police say they found at least one underage pregnant girl.
Police officials say that failing to disclose an underage pregnancy is an offence in itself.
"Making an underage female [pregnant] constitutes statutory rape. It is also an offence not to inform about that offence to the authorities," superintendent (SP) Ajith Rohana told BBC Sinhala's Saroj Pathirana on Monday.
The church denies wrongdoing, saying children and mothers are looked after at the shelter which is registered for this purpose.
Sister Eliza is expected to appear at a magistrates' court on Thursday. Charges have yet to be filed.
The BBC's Charles Haviland in Colombo says this is an unprecedented incident for the religious order founded by Mother Theresa in Calcutta. The head of the Missionaries of Charity religious order is now in Sri Lanka for consultations.
The Missionaries of Charity have had their controversies, but never until now has one of their sisters been imprisoned, our correspondent reports. Sister Eliza, an Indian national, was kept in a high security prison for several days after her arrest.
The Indian High Commission is also monitoring the case.
The police raid came after a report from Sri Lanka's National Child Protection Agency (NCPA) that claimed Sister Eliza was suspected of selling children under her care and other related abuses.
But the Archdiocese of Colombo has categorically denied this; its website says money has never been exchanged for children. There are no charges in connection with this allegation.
A church statement said: "We never involve in selling these precious lives of the children and never take money for our work."
The church also accused the media of trying to stoke public anger over the issue.