The police officer criticised by a coroner yesterday over his role in the search for toddler Aisling Symes is on stand-down from frontline duty after assaulting a teenager.

Constable Gareth Needham gave evidence at the inquest into the death of the West Auckland toddler.

In December, he was found guilty of assaulting a teenager and is to be sentenced on Monday.

The inquest heard how Aisling - who would have been 4 yesterday - disappeared on October 5, 2009, while her mother, Angela Symes, was cleaning out her late parents' home.

Seven days later, her body was found 36m down a stormwater pipe.

Mr Needham was one of the police officers who responded to a 111 emergency call. He found a manhole cover upside down and slightly out of place near where Aisling was last seen.

He told the inquest he lifted the cover, which weighed about 20kg, put his head inside the manhole and used a torch to check up and down the drain.

"I called out 'Aisling'. There was no response."

He said he did not mention the manhole cover to his supervisor "because I thought it was impossible Aisling could have gone down the manhole because of the weight of the cover."

Under questioning from coroner Garry Evans, Mr Needham said he did not complete a police job sheet on the drain because it was "only one of a hundred places that we searched".

Mr Evans: "We would have made much better purchase if you had discussed your findings with your supervisor on the fifth or sixth [of October]?"

Mr Needham agreed, but said he had told a Search and Rescue member about the drain when he was posted as scene guard later that night.

He said he had searched "hundreds of places where a little girl could have got into trouble".

Mr Evans asked: "What have we learned?"

Mr Needham replied: "To record as much as practical, and to be honest, sir, it was not possible to record every single place and I think you're being unfair."

Detective Senior Sergeant Jillian Rogers told the inquest it was up to individual officers to decide what was relevant to record, but she believed the manhole cover was "highly relevant".

"The information clearly needed to be passed to his supervisor."

Under questioning from Mr Evans, Ms Rogers said: "As you said, sir, we missed a big clue."

Search and Rescue leader Senior Constable Darren Calkin said that at no time was he made aware that Mr Needham had found the manhole slightly open.

If he had been, he would have investigated further.

Needham and Constable Alan Michael Douglas were found guilty of assaulting Joshua Hart, 18, in a West Auckland park in February last year.