Detectives investigating a brutal 1995 cold-case murder have received new "information of interest" since announcing a $100,000 reward yesterday.

Angela Blackmoore, a 21-year-old mum who was 10 weeks' pregnant, was stabbed 39 times in her house on Vancouver Crescent in the Christchurch suburb of Wainoni on the blustery, warm Thursday evening of August 17, 1995.

Her 2-year-old son Dillon was sleeping in his bedroom at the time of her death.

Her partner, Laurie Anderson, discovered her body when he returned home after work at 11.20pm that night.

Police never found her killer, despite interviews with hundreds of people, and the case has remained open for more than two decades.

Yesterday police launched a new appeal for information offering a record $100,000 reward.

Detective Sergeant Todd Hamilton said on Sunday they had received 11 calls through the 0800 number, and others had provided information through social media.

"Certainly there's some information of interest that we will be following up," Hamilton said.

"We cannot comment on the nature of the information provided nor its significance to the inquiry at this stage.

Police are really pleased with the public's response to the reward and we encourage people to continue to come forward with information."

Anderson was confident the case would finally be solved.

"The scum factor, who knows who's done it, only care for themselves. So now there's an interest for someone to make a gain, [the killer] will be very scared," the 54-year-old told the Herald yesterday.

Time has done little to ease Anderson's pain and suffering at losing the woman he loved.

"It's virtually the same as when it happened," he said.

"It's still raw, you just learn to live with it. It's like a disability – say you lost your arm – you learn to live with your loss."

Investigations manager Detective Inspector Corrie Parnell said it was a "horrific" crime which took the life of a young mother "with her whole life ahead of her".

"Since Angela's murder our focus has been on bringing the person responsible to justice, and although many years have passed that focus has not changed," Parnell said.

"With the passing of time allegiances may have changed and we're appealing to anyone with information that might help, no matter how small or seemingly insignificant, to contact us."

The reward money would only be paid out if the tip-off led to the murderer being, firstly identified, and then convicted in a court of law.

The file has been reviewed several times over the past two decades.

More than 100 people have been spoken to during the course of the investigations.

However, there's never been enough evidence to lay charges.

Today there are fewer than 10 persons of interest remaining who haven't been ruled out, Parnell says.

While 24 years have passed, Parnell believes the killer's "cognitive load of burden" will not have passed.

"I encourage them to come forward, and secondly, anybody that may have been of assistance in the crime, or has material information or was close to those persons involved, that same burden will be present, and I encourage them to come forward," Parnell said.

Fingerprints were taken from the house and remain unidentified. They have been kept on the police national DNA database, along with other items taken from the scene, and are regularly checked as advances in DNA testing keeps getting better.

Parnell said you live in hope of one day getting a call from forensic experts who have nailed a trace match.

Anyone with any information about the case can call a dedicated police phone number, 0800 22 1995.