South Yorkshire detectives who spent over six years and £2 million solving a murder case have vowed to continue searching for the victim's body.
Mother and son, June Buttle and Jason Thaxter, are both behind bars for killing 54-year-old Thomas Groome, who vanished in January 2010.
Buttle, in her 50s, was jailed for 16 years in 2015 after admitting manslaughter.
Her son was jailed for life yesterday and ordered to serve a minimum of 30 years after being found guilty of murder.
The case against the pair is that they killed Mr Groome for a 150,000 euro compensation pay-out he had received.
Thaxter, 39, from Hexthorpe, is also said to have 'hated' Mr Groome, who was her mother's lover and had been abusive to her during their 10-year relationship.
Buttle initially covered her tracks by pretending that Mr Groome had gone to Portugal to start a new life and using his Facebook account to write posts.
She later confessed to friends that she had killed Mr Groome with her son by hitting him over the head and dismembering and burning his body.
But she refused to implicate her son when quizzed by police and was jailed alone.
A confession Thaxter made to an ex-partner helped secure his conviction this week.
Jailing Thaxter, Judge Justice Globe said the complex and lengthy police probe had cost £2 million.
Temporary Detective Chief Superintendent Lisa Ray said: “At the conclusion of the court case, the Judge requested information pertaining to the costs of this lengthy, six-year investigation.
“This inquiry spanned a number of different countries, including Ireland, Poland and Portugal, and a range of different agencies whose costs for their time, officers and staff are largely unknown so these have had to be conservatively estimated.
“I want to take this opportunity to thank those forces and agencies that have worked alongside us for many years in order to secure justice for Mr Groome’s loved ones.
“It’s important to point out that the cost to South Yorkshire Police includes the salaries of the officers and staff involved throughout our inquiry, which over the course of six years has totalled over 60 people who have each provided their skills and expertise at one stage or another.
“The salaries of those officers, therefore, are of no additional cost to the force but are costs that would normally have been incurred as daily business.
“While the successful conviction and sentencing of both Buttle and Thaxter are satisfying and are credit to the hard work and dedication of the officers and staff who have played a role in this investigation, Mr Groome’s family remain unable to put their loved one to rest.
"We will continue our work to find answers to the questions asked by Mr Groome’s family about what happened to him and our efforts to find Mr Groome’s body remain ongoing.
“We will pursue any and all avenues of investigation, so if someone does hold any information that could help us, please call 101 or report this to police.”