Detectives have revealed how the porcelain remains of fake teeth revealed Klaus Andres' shocking murder of his wife before he dissolved her remains in acid.

The hideous truth about what happened to Li Ping Cao in October 2011 was uncovered by detectives in the days after her disappearance.

She met her demise in the house she shared with Andres in a way that shocked even the most-experienced of detectives.

Ms Cao was a single mother-of-one looking for a better life when she met Andres online.

After a few months, he travelled to China so that pair could meet in person.

She eventually moved to Cairns to marry him and in the beginning the newlyweds were happy.

Li Ping Cao was dissolved in acid after being murdered by her husband (Source: A Current Affair)

But in November 2011, Ms Cao's friends reported her missing.

Police appealed for information and Andres addressed the media, smiling at the cameras and saying his wife of seven years had left him after a heated argument.

He claimed she had accused him of having an affair.

This was the only truth to his story. Police uncovered emails between Andres and a Thai woman. He had taken photographs of the pair while his wife was visiting family.

In the days before killing her, Andres had also forged Ms Cao's signature on a letter to Centrelink asking for her payments to be transferred into his bank account.

Police also discovered Andres had used his wife's credit card several times after her disappearance, including at a hardware store.

Klaus Andres initially appealed for information surrounding his wife's disappearance (Source: A Current Affair)

"We viewed CCTV and quickly established that it was Andres who had been using her Commonwealth Bank card to purchase hydrochloric acid and obviously, that was of major concern to us," Detective Sergeant Brad McLeish told A Current Affair .

"We established that he'd not only purchased acid on that day, but a number of days, and he'd purchased a total of 60 litres of acid - which is an enormous amount of acid to buy.

"My initial thoughts were that he's used the acid to help in the cleanup after the murder."

Several days after the discovery, Sergeant McLeish was interviewing Andres while police searched his home.

"Forensic officers examined the stormwater drain out the front of his house. There was a large stormwater drain directly out the front of his house and we discovered porcelain false teeth in the drain," Sergeant McLeish said.

"That, for us, cemented the fact that he had committed this despicable crime against his wife."

A picture of him smiling while appealing for information had police concerned (Source: A Current Affair)

Police came to the conclusion that Andres had used the acid to dissolve Ms Cao's remains over a period of several days.

But for Sergeant McLeish, explaining to Ms Cao's family exactly what happened to her was even harder than piecing the evidence together.

"Telling family that they're never going to be able to take their loved one home or to have a proper burial, that type of thing, that was tragic for the family," he said.

"It's a shocking crime, it's a shocking thing to do.

"I don't like to use the word psychopath, but that's his personality.

"He's just an evil, greedy, arrogant little man."

Andres was sentenced to life behind bars for the murder of his wife and will not be eligible for parole until 2028.

Detective Sergeant Brad McLeish will never forget the clue that led him to believe Andres was responsible (Source: A Current Affair)