A mother-of-two arrested last week under a 2009 deportation order has claimed her children were "abandoned" by gardaí and are now missing.

The woman, who is from Nigeria, is challenging her deportation and has taken High Court proceedings aimed at securing her release from prison.

She claims gardaí placed her children, aged eight and five, with "unknown" persons following her arrest and that they are now missing.

Lawyers for the State have disputed the claims.

Mr Justice Michael White adjourned the case until tomorrow.

The woman's barrister told the High Court this morning that the case was urgent as the children were "of a tender age".

He said they were not given over to the care of the Health Service Executive after their mother's arrest and were now in "an uncertain situation to put it mildly".

It has not been clarified as to where they are, he said.

However counsel for the State Anthony Moore told the High Court this morning the woman's claims were "completely wrong" and "wildly inaccurate".

He said she had been evading deportation since 2009 and was discovered by gardaí last week.

Mr Moore said gardaí will say the woman gave written consent for her children to be placed with a friend and that they had gone missing when gardaí later went to collect the children to deport them.

Mr Moore said gardaí believe the woman knows the whereabouts of her children or the people caring for them.

In a sworn statement presented to the High Court, a solicitor for the woman said the "quasi detention and abandonment of the children in to the care of unknown persons appeared reckless" and was contrary to the Child Care Act and the UN Convention on the Rights of the Child.

He said the children had been traumatised by being placed in the custody of Garda National Immigration Bureau officers.

The woman claims to have been trafficked into Europe for sexual exploitation in 1998.

She had been living in Dublin where her children had attended a local school.

Her lawyers said new evidence of her having been trafficked should be considered by the authorities before a final decision is made.

Mr Justice White said there was an obligation on the woman to file a new sworn statement outlining the full history of her case, as many of the details of her case had not been included when it first came before the court.