The NSW Police Force failed to arrest a man for distributing child abuse material, despite being sent a brief of evidence in August 2013 by the Queensland Crime and Corruption Commission (CCC).

Key points: A man was arrested for distributing child material in November 2014

A man was arrested for distributing child material in November 2014 He adopted a foster child in his care two weeks before the arrest

He adopted a foster child in his care two weeks before the arrest NSW police received evidence on the man's behaviour in August 2013

NSW police received evidence on the man's behaviour in August 2013 NSW police failed to notify the state's family and child services a child was in his care.

It took a second CCC referral more than one year later, in October 2014, for NSW police to arrest the man on November 3 of that year.

The delay allowed the man, who cannot be named, to formally adopt a young foster child in his care two weeks before his arrest.

NSW police chose not to notify the NSW Department of Family and Community Services (FACS) there was a child in the man's care.

The case led to a new FACS procedure regarding checks of prospective adoptive parents.

The NSW Ombudsman is now investigating the police handling of the case.

The man's wife and adoptive mother of the now eight-year-old girl told the ABC she had no idea her husband was watching and distributing child abuse material.

She said she was blindsided when police first came to her home last year.

"Absolutely sick to my stomach. Couldn't believe you could be with someone and be under the same roof and not know anything that they were doing," she said.

"Absolutely shattered and devastated for my daughter more than anything."

She said she did not believe her now-estranged husband abused her daughter.

"She got assessed by the department, and also there wasn't enough time. She was always with me," the woman said.

Adopted girl's great uncle lashes out at NSW police

The girl was formally adopted by the man and his wife on October 24, 2014, when she was seven years old.

She had been in their care since she was two years old, after being neglected by her drug-addicted parents.

Her foster father was arrested and charged with possessing and distributing thousands of child abuse images on November 3, 2014.

There is no evidence he abused his now adopted daughter, however, her birth relatives were worried abuse may have occurred.

"There's always that fear," her great uncle, who cannot be identified, told the ABC.

"How could they possibly leave a child in that situation knowing that he was into child pornography?"

He lashed out at the failure by NSW police to arrest the man in 2013 and to notify FACS he had a child in his care.

"What sort of an investigation is it if they don't know there's an adoption about to take place?" he said.

"And to leave a child in that situation, a seven-year-old, is a terrible crime."

The great uncle asked the NSW Ombudsman to investigate the case, but was initially told the it did not find any fault with NSW police.

However, after being approached with more information by the ABC, the ombudsman is now reinvestigating.

"One of the issues we will be considering is the timing of the making of a risk of significant harm report by the NSW Police Force to FACS," a spokesman for the ombudsman's office said.

CCC says it referred evidence to police in August 2013

Under its powers to investigate organised crime, CCC identified the man accessing and sharing child exploitation material online in July 2013.

On August 2, 2013 the CCC said it referred its evidence to the NSW police after discovering the man lived in that state.

A NSW police spokesman said in a statement: "Nothing in the referral indicated there were children at risk, nor did it suggest that this person was involved in, or planning to engage in, contact offences with children."

"Based on the evidence at hand the matter was prioritised accordingly."

On September 30, 2014 the CCC said it identified the same man, using a different online identity, accessing and sharing child exploitation material.

The CCC said that over a few days "the user made statements suggesting the possibility of children at risk".

The CCC found it was the same man it had identified in 2013 and discovered he had a child in his care.

The CCC said it then "urgently disseminated all relevant information ... to the New South Wales Police Force" on October 8, 2014.

NSW police arrested the man at his home on November 3, 2014.

But police did not inform FACS at any stage that a child in his care may be at risk.

Girl remains in adoptive mother's care

The man recently pleaded guilty to possessing and distributing thousands of child abuse images in a NSW court and was sentenced to 16 months in jail.

The girl was formally adopted by her foster parents on October 24, 2014 less than two weeks before her now adoptive father's arrest.

The girl remains his legally adopted daughter despite the man now being placed on the Child Protection Register.

The NSW Department of Justice said in a statement to the ABC: "The registration does not prevent them [offenders] from having access to their own children."

FACS refused to comment on the case, but confirmed it had changed its procedure for prospective adoptive parents.

"Practice now requires a national police check to be undertaken as close as possible to filing the adoption court application," a FACS spokesman said.

An adoption is a permanent order, and can only be changed by the Supreme Court if proven it was obtained by fraud, duress, improper means or in other exceptional circumstances.

The girl remains in the care of her adoptive mother, who is estranged from her jailed husband.

The mother told the ABC she would fight any attempts by her husband to access the child when he was released from jail and she had initiated divorce proceedings.