The child shot dead in Clonmel could have been reunited safely with her mother if the case had been taken more seriously from the beginning by Garda authorities, said Ms Mary Banotti MEP yesterday.
However, she said she recognised that the Garda had done "very intricate police work" on the case in recent times.
Ms Banotti is the European Parliament president's mediator for trans-nationally abducted children.
She suspected that Mr Crowley had got a considerable amount of help from a number of people to enable him to keep Deirdre and escape detection.
Ireland should consider legislation similar to that in Britain which allows a High Court-appointed official to go to the house of anyone suspected of colluding in the hiding of a child and, if necessary, arrest them.
"Speed is absolutely essential. People can disappear terribly quickly. I think if this case had been taken more seriously right from the beginning by the gardai, they would have got the child back," she said.
She had been involved in helping Deirdre's mother to check if the child was being kept in Wales or France. "We have all been involved doing everything we could. Deirdre's mother is an extremely impressive person," she said.
Stressing she was "gender-neutral" on the custody of children, she said she had never known a situation where there were fears for the life of a child abducted by his or her mother. However, she had known of several situations in which fathers had abducted children and there was cause for concern.
Ms Banotti is a member of the board of the Irish Centre for Parentally Abducted Children. It can be contacted at 01-6620667.