A child sex offender was strangled and dismembered in his Deptford flat.
Noel Brown, 69, was found dead alongside his daughter Marie Brown, 41, in his flat on New Butt Lane in the early hours of December 4.
Police believe Mr Brown may have been killed late at night on November 30, and that his daughter interrupted his killer dismembering her dad’s body two days later and strangled her too.
“Parts of both his arms and a part of one of his legs have been removed from the scene and those have not been recovered,” he said.
“In my 27 years of policing, I have not seen anything quite like this.”
Detectives are keeping an open mind over the motive, but are investigating whether Mr Brown’s murder was linked to his 1999 conviction for a child sex offence.
Ms Brown leaves behind two daughters and her family have said they are still in “shock and disbelief” that anyone would attack her.
In a statement by her family, it said “no one should ever have to feel this pain”.
It read: “As a family we are struggling to put together an appeal because we are still in shock and disbelief.
“Marie was the peacemaker and we cannot understand why this would happen to her.
“Marie was everything and we miss her so much, we are hurting and this is painful and we don’t want this to happen to someone else.
“Marie was a calm peaceful person, slow to anger and quick to forgive, she never got caught up in any sort of fight and avoided feuds with anyone because she didn’t want to be a part of anyone’s upset.
New CCTV footage released shows a suspect walking towards New Butt Lane on December 2.
The footage shows a man in a dark hooded top walking along Deptford Broadway and Reginald Road around 5am on December 2.
Inspector Harding said: “It is extremely important that we find out who this man with the rucksack is as he is now of very significant interest to our investigation.
“We really need the public’s help with this case so that we can bring to account whoever is responsible for this appalling double murder that has left Noel’s family deeply upset and Marie’s two daughters motherless, and the wider family utterly bereft.”
Anyone with any information is asked to contact the investigation team on the dedicated incident room number – 020 8721 4205, or via 101. You can also tweet police @MetCC. To remain anonymous please call Crimestoppers on 0800 555 111.