A little boy was left concussed after falling down a drain shaft with a suspected faulty manhole cover.

Mum Amy Blyth has told of the "horror film" moment her 18-month-old son disappeared through the hole, before the metal drain cover closed on top of him.

Watch the awful moment Theo fell down the drain

The nightmare moment happened at about 9.30am in Beecholme Drive, Ashford, where Amy's mum lives.

"We were just walking out for him to go to his dad's house," recalls Amy, 23, from Tenterden. "I saw the drain was a little bit loose. I didn't realise to [what] level it was loose.

"He ran to the drain, stood on it, and just fell the whole way through.

"And then the drain lid shut on top of him."

A CCTV camera on a nearby house captured the bone-chilling moment, as little Theo disappeared from view and Amy sprang into action.

"My first thought was 'oh my God, he's dead'," she said.

"I yank the drain lid out, and I just see him down there, screaming my name. There was sewage up to his knees.

"I jumped down the drain, but it's not big enough for me to bend over to grab him. I had to sort of arch my body to grab him and pull him up.

"I don't know how I did it. My body went in ways I've never bent before, just to get him out of that drain."

Amy stood on ledges at the side of the sewer, reaching down to Theo who had fallen to the very bottom.

"It was so deep you couldn't see my head from the ground, and I wasn't even on the floor," she said.

"Just as I pulled him up I think someone flushed a chain because we were soaked - with I think, possibly, wee.

"Our clothes are absolutely disgusting."

Amy emerged from the drain "screaming for help", while Theo was in an apparent state of shock, and "wasn't really making a noise".

The terrified mum rushed Theo - who is said to have swallowed some sewer water - to Ashford's William Harvey Hospital.

There, medics diagnosed him with mild concussion, but x-rays revealed he miraculously got away without a broken bone.

"It could have ended up so much worse," said Amy. "If he'd gone down head first, I don't even know if he would be here.

"It makes me feel sick to think of it.

"It's an absolute nightmare - I'm petrified of drains now. I still feel really shaken from it. I just can't really get over it.

"He literally went straight to the bottom, and I thought I was going to lose him.

"It was actually like a horror film."

Amy says she dreads to think what might have happened had a child fallen through the drain cover unseen.

"If he'd been on his own, or if it had been another kid on their own, we wouldn't have found him," she said.

"We wouldn't have known where they'd gone.

"You couldn't even hear him because it's sound-proof.

"He could have fallen down and I'd have gone running round the block trying to find him, not in a drain."

Theo is now home and doing well.

But Amy has complained to Southern Water and says she "needs answers".

She believes the drain has been faulty for some time.

"My little boy shouldn't have fallen through a drain," she said. "It's not acceptable.

"We need some answers to why it wasn't fixed."

It is understood Southern Water is working to establish who is responsible for the drain and manhole.

The utility company has confirmed it is investigating and taking the matter "very seriously".

A spokesperson said: "We are aware of a situation involving a child and an open manhole.

"This is clearly an upsetting situation for those involved and our team is on-site. A dedicated customer liaison officer has been assigned to support the family.

"We are taking this matter very seriously and our first priority was to make the area safe. Next steps are to understand exactly what happened."