A Christchurch house where a pensioner and her son were found dead in a suspected murder-suicide is on the market.

Beverley Joan Mcilraith, 80, and her son Nick Myles Mcilraith, who was in his 40s, were found in separate rooms of an Ayr St, Riccarton house on April 2 this year by police carrying out a welfare check.

A member of their family had raised the alarm after the pair could not be contacted.

Inside the house, on the corner of Ayr St and Mona Vale Ave, the officers made the double grim discovery of the pair's bodies.

It's understood they had been dead for some time, with a source earlier telling the Herald it was "a number of days" and "possibly up to three weeks".

Police at the scene of the double death in Christchurch. Photo / George Heard

The deaths have been referred to the coroner. A Ministry of Justice spokeswoman confirmed yesterday that the case is still active.

Meanwhile, the mock Tudor house has been listed for auction, "as is where is".

Commerical cleaners moved into work at the Christchurch house where a woman and her son were found dead in April this year. Photo / George Heard

An advert posted on Trade Me by Mike Pero Real Estate says the multi-storey three-bedroom townhouse, which has a rateable value of $360,000, offers an "exceptional opportunity" for prospective buyers.

No mention of what happened inside the house earlier this year is mentioned in the property listing.

Instead, it highlights the property's "premium location" with Hagley Park "right at your doorstep", just three minutes from the city centre, and being in zone for some of the city's top secondary schools, including Christchurch Girls' High School just around the corner, Christchurch Boys' High School, and St Thomas of Canterbury College.

"Opportunities like this do not come around every day," it says.

When the Ayr St house became subject to intense police scrutiny, its appearance was rundown and unkempt, with its exterior and some windows covered in ivy. Outside, the garden and driveway were overrun with weeds and plants.

However, it's since been tidied up, inside and out, with its interior stripped out.

The auction is scheduled for September 14.

Mike Pero Real Estate declined to comment on the auction when approached by the Herald, saying it was a "sensitive subject".

In the days after the grisly find, Detective Senior Sergeant Colin Baillie confirmed that a homicide investigation was launched after the post mortem examinations.

"No one else is being sought," he said at the time.

"Our thoughts are with the wider family and they are being supported by Victim Support."

He confirmed "no one else is being sought in relation to the incident" and that police were in close contact with a number of members of the Mcilraith family about the investigation.

"Our thoughts are with the wider family and they are being supported by Victim Support."