The drain where the body of Aisling Symes was found has been complained about four times in the past five years and at least one person raised safety concerns after a back-log of water blew the manhole cover off.

A homeowner said she complained to the council only two weeks ago about the lid coming off the manhole above the drain where Aisling was found.

Waitakere City Council has confirmed a complaint was received 24 days before Aisling went missing. The council also confirmed that it had received four complaints in total, dating back to 2004.

Police last night found the two-year-old's body in the stormwater drain at 5 Longburn Rd, about 20m from the home of Aisling's deceased grandparents at No 7, from which she went missing last Monday.

Council spokesman Wally Thomas said six days after a complaint was received on September 10, council contractors found large willow tree roots in the drain and began "the process of deciding how best to go about removing them".

Asked if that decision was made before Aisling went missing, Mr Thomas said: "No, sadly, not."

Mr Thomas said the council flushed the drain out in 2007 after it silted up and that sometime between 2007 and 2009, tree roots had blocked the drain up.

"Any speculation of how she got into the pipe is just that, speculation," Mr Thomas said.

Longburn Road landlady Stacey Baker said she made the most recent complaint to the Waitakere City Council a week before Aisling disappeared, after heavy rain moved the 20kg lid of the stormwater drain which was found ajar on the day Aisling went missing.

Her current tenants used to live next door to number 5 Longburn Road and moved across the road into Ms Baker's house because of the flooding the drain creates, she said.

"The council actually told me that the lid blows off number five," Ms Baker said.

She said she had complained about the problem for years. Her tenant Sonya Carrington told nzherald.co.nz that the main reason she moved across the street was "because I didn't want my kids down that drain".

Ms Carrington said the discovery of Aisling's body in the drain after the history of complaints was disturbing.

"It's disgusting - that's what makes me sick."

Police search

Police and later Aisling's father searched the drain on the day she went missing but her body was not found until about 8 o'clock last night.

Police inquiry head Inspector Gary Davey said the drain was also searched with cameras, however, the cameras could only go 9m into the drain and found nothing.

He said police and fire fighters began five hours of digging up the drain yesterday because he was "not happy with that part of the search".

At a media conference this morning, Mr Davey said there had been a history of the drain blocking.

He said it was raining at the time Aisling went missing and that it would not have been possible for her to turn around inside the drain.

"Whether it was washing her down or she was crawling down, we just don't know," Mr Davey said.

He said the drain cover had been up to 12cm ajar when a police officer came across it on the day she went missing. Mr Davey said the officer searched part of the drain that he could get into with a torch and called out to Aisling but could only hear running water.

He said the manhole cover was about 600mm wide and weighed about 20kg, something well beyond the capacity of a child to move.

"It is still too early to say exactly how Aisling has got into the drain or how long she's been there. I believe she has been there from the start and that it is mis-adventure but I can't rule out any other possibilities at this stage," Mr Davey said.

Asked why the drain was searched a fourth time, Mr Davey said police had hit a brick wall in their investigation.

"It was the fact that all of our lines of inquiry were not really leading us to anywhere positive, there was no further sightings of Aisling and the Asian woman was proving very difficult to find," Mr Davey said.

He was also asked if the drain was blocked when Aisling went missing.

"Ok, I'm going to draw the media conference to a close there. As you can appreciate, I'm still trying to get my head around all of the information," Mr Davey said.

He said a post-mortem examination on Aisling is being carried out today and there would be more information available then.

Waitakere Mayor Bob Harvey earlier told TVNZ's Breakfast programme the only way Aisling could have got into the drain was through a manhole cover.

The cover was somehow put back over the hole after the toddler went through it, he said.

"The drain goes down into a very narrow pipe - about 15 inches across - and it's full of weeds and roots of a massive, massive willow and that's where her body came to rest before it keeps going and connecting with other pipes."

He said it would have been impossible for Aisling to prise the manhole cover open by herself.

"I would have struggled with it myself," he said. "It's had to be opened at some stage."

- with NZPA