As cremation continues to increase in popularity, it gives rise to an uncomfortable question — what happens to the gold fillings, stainless steel plates and titanium hip replacement parts that are left in the ashes?

Key points: After cremation, metal body parts can be recovered and recycled

After cremation, metal body parts can be recovered and recycled The Karrakatta recycling scheme has so far raised $300,000 for WA charities

The Karrakatta recycling scheme has so far raised $300,000 for WA charities The scheme is growing each year as more people choose cremation over burial

WARNING: Some readers may find the images below confronting.

Perth's Karrakatta Crematorium has come up with a novel answer that avoids these precious metals being consigned to landfill, while also providing a benefit to charities.

Since 2013, the crematorium has sent more than 19 tonnes of precious metals to the Netherlands to be melted down as part of a precious metals recycling program.

In the process it has raised more than $300,000 to help cancer patients.

Part of a global recycling effort

Metropolitan Cemeteries Board CEO Peter Deague said when he first heard about the program, he saw tonnes of potential in the metal body parts that used to be buried in a pit in the cemetery grounds.

The material was dug up and sent to Dutch company OrthoMetals, which deals with over 1,200 crematoria worldwide.

After cremation, intact metal implants are covered in a fine metal dust that can also be recycled. ( ABC News: Kate Leaver )

The company separates the metals, sends them to the smelters, examines the spot price and then sends a payment back to the crematorium.

Mr Deague said the program raised $40,000 for Karrakatta in its first year, while the latest shipment had raised $180,000.

Sorry, this audio has expired Crematorium ashes helping cancer patients

He said the crematorium did not rush into taking part in the program.

"[First] we looked at the legal aspects, we approached the State Solicitors Office to see whether we actually had the legal right to recycle the metals," he said.

"From that process I reported to the board that I thought the funds we receive from recycling should be donated to charity.

"So we donate to the Cancer Council WA for patients who are going through cancer treatment.

"To date we've donated just over $300,000 which we had never envisaged from recycling the metals."

There has been a steady rise in cremations, and the use of metal implants. ( ABC News: Kate Leaver )

Mr Deague said there had been a recent steady increase in families opting for cremations, with more than 80 per cent choosing the method over burials, leading to an increase in metals being collected.

"We pick out the most obvious ones, the hip joints and larger ones, but then we have a cremulator which is a machine which filters the human ash, and that extracts some other metals as well," he said.

"When you see what's left, it looks like ash but it's actually fine metals.

"There seems to be a heck of a lot of metal hip joints.

"It's a bit of a surprise sometimes when you look into the containers. It ranges from titanium, to cobalt, to stainless steel and a bit of gold.

"The last time that we sent it over to the Netherlands there was quite a lot of gold in those ash remains, which is a very fine powder."

Family members can opt out of scheme

Andrew Fox and Peter Deague from the Metropolitan Cemeteries Board say the scheme is growing. ( ABC News: Kate Leaver )

Recycling of metals after cremation is commonplace in many countries across Europe and in America, and the program operates on a opt-out process for family members before a body is cremated.

The most recent recipient of the proceeds was the Cancer Council's Milroy Lodge for regional residents receiving cancer treatment in Perth.

WA Local Government Minister David Templeman, who presented the $180,000 donation cheque this week, said the partnership between the Cancer Council and the Metropolitan Cemeteries Board was unique.

"We know that every year $150,000 or so will be able to be committed, so there will be a steady contribution coming from this unique recycling opportunity," he said.

About 5,000 cancer patients and their families stay at the Cancer Council's Milroy and Crawford lodges each year.