The family of Indian-origin man Avtar Singh Kolar and his English wife have described them as the "sweetest and kindest people" as the British police said they were following "a number of lines of inquiry" into their murders.
The bodies of Avtar, 62, and Carole, 58, were found by their police officer son, Jason Kolar, from their house in Birmingham on Wednesday. There has been speculation that they were killed allegedly as revenge by someone affected by their son's work in the West Midlands Police.
Speaking to mediapersons, two of the deceased couple's children, Michelle Kirwan and Avtar Kolar described their heart-break at the murders and appealed for information from the community to help solve the murders. The couple has four children and eight grandchildren.
Michelle Kirwan said: "The light was switched out in our lives and our hearts have been broken forever. My mom and dad were the sweetest, kindest people that I have ever met and would do anything for anyone.
They were the beautiful parents of myself, Jason, Taz and Marie, and the precious Nanna and granddad of eight grandchildren, who adored them with all their hearts".
She added: "As a family we could not have been closer. We did everything together, holidays, Christmas, birthdays and weddings. We adored each other and loved each other so much.
Whoever has done this has not taken just two lives, but a further 16. Our hearts are broken forever and our lives will never be the same."
Avtar Kolar said: "We are all struggling to come to terms with this tragedy. We are all hurting so much inside because they were so special. Not only to us, but to everybody who ever met them. They wouldn't hurt a fly and we just can't understand how this can happen".
Detective Superintendent Richard Baker, who is leading the murder investigation, said: "We are pleased with the response from people so far in coming forward with information but we are keen to hear from anyone else with information that will help us solve this horrendous crime".
He added: "We are still investigating the circumstances surrounding this attack however this is a very complex investigation and we are continuing to keep an open mind. There is nothing at this stage to indicate that the fact that the couple's son is a serving police officer had anything to do with their deaths."
The police said post-mortem examinations would start later, and added that forensic officers were on still on the scene and they were currently viewing CCTV footage from the area.