It's been 11 years since her son's death, but the grief is now as raw as ever for Teresa Smith-Craig after a precious taonga was stolen from his grave.

It was a crime the thieves would have been prepared for as the large, rock-sized, greenstone had been bolted to the headstone of Isachaar Smith-Craig's grave at Mangaroa Cemetery near Hastings.

It was only there for about a week before it was stolen.

Isachaar was the youngest of Smith-Craig's six children, when he was born at the end of January 2000.

Just 11 months later, he came critically close to death after crawling into the pool of their Hastings home.

He survived but suffered severe brain damage. He was wheelchair-bound, unable to walk, talk, eat or fend for himself.

Neither Smith-Craig or the rest of the whānau minded though, as he was alive, breathing. That's all they cared about.

She said his survival brought the family closer together, taught them about compassion, love and to be grateful they each had all their "bits and pieces".

However, a chest infection would eventually knock him down. He died aged 7 in April 2007.

Smith-Craig said she buys each of her children a greenstone when they turn 18, but for Isachaar she had to do something different.

She asked a favour of a friend in Canterbury to find her a greenstone she could put on his grave. He walked in a local river, continually saying a prayer and thinking of Isachaar.

After three hours he put his hands in the water and found giant rock of pounamu, and carried it for three hours to bring it out.

Smith-Craig had the taonga below her son's photo which sat on the mantelpiece of their home. They would rub it, and say Isachaar's name, pray for him and share stories.

The massive pounamu sits bolted onto Isachaar Smith-Craig's grave at Mangaroa Cemetery on the outskirts of Hastings. It was stolen within a week of being installed. Photo / Supplied

She wanted to put it on his headstone, but her mother didn't want her to, saying it would only get stolen.

"My Mum, who is fluent in [Te Reo] Maori, said 'don't take it there, it will get stolen' and 'keep it at home'. But the friend who got it for us, got it for his grave.

"I thought he's 18 now, I better do this because it was gift for me to do that."

She kept it at home for a couple of years before late last year deciding to get it fixed to her son's grave.

The company who made the headstone agreed to fix it in place, drilling two bolts through the stone, setting it in place, co-incidentally on the day of his near-drowning 18 years earlier.

Feeling satisfied, Smith-Craig went to Wellington for a relative's 40th.

She spoke to her daughter the day before she got back and was asked whether she had got it installed yet. Then the alarm bells rang.

Arriving back the Sunday before Christmas, she visited his grave to find it gone.

"It's pretty heart-wrenching. I was so upset and thought who could do that. It was bolted down with two big holes in it ... I got it done properly because I knew that it was a great piece of greenstone."

She described her friend's long walk through the river as a spiritual experience and she now felt sorry for him and all the effort he'd put into it.

"Karma will come back on them. So I feel quite sorry for the person that's stolen it, because you can't do that, because it's Māori. Karma will come back on them really badly."

She received the invoice for the greenstone installation on Saturday. Getting it made her cry.

"I haven't even paid for it yet ... so that made me cry and another new year made me cry because it's his birthday at the end of the month. It's really upset all his family, too."

She's now pleading with the thieves to return the greenstone to their family, which also includes his sister born three years after him.

"I would like them to put it back. Just put it back, I mean it's probably too late for them now anyway, the boogie man is probably walking around with them right now, but just give it back."