Police discovered the remains of Henriett Szucs and Mihrican Mustafa in April 2019 when they were called to a London residence to make a welfare check on Zahid Younis, the man convicted of killing them.
Younis was not home, but when police entered the residence, they discovered flies gathering around the freezer.
Zahid Younis was convicted of murdering two women and sentenced to life in prison by a UK court.
Detective Chief Inspector Simon Harding testified that the officers forced open the freezer after experiencing "an old-fashioned police hunch" and made the grisly discovery.
"He broke open the freezer and discovered what could only be seen, at the time, as only one body," Harding said.
"It actually took the freezer being taken away and X-rayed for it to be seen there was another body underneath that. It was a gruesome discovery for the officers," he said.
The bodies of Mihrican Mustafa and Henriett Szucs were discovered in a freezer at his apartment in April 2019.
Szucs, 32, who is originally from Hungary and lived with Younis, had been missing since 2016. Prosecutors said Younis bought the refrigerator in November of that year, "for the sole purpose" of concealing her body, shortly after she was killed, according to reports by the BBC.
Younis admitted to putting her body in the freezer but not to actually killing her and told police that she died while he wasn't home and he panicked. He said he paid a man to help him get Szucs' body into the freezer but the man later blackmailed him into adding Mustafa's body to the storage as well.
Mustafa, 38, went missing in May 2018, police said.
Both victims were "vulnerable women living somewhat chaotic lives", including periods of homelessness and drug addiction, according to prosecutors.
Authorities could not determine the cause of death but said the women were badly bruised and suffered violent deaths, with both sustaining numerous rib fractures.
Szucs sustained "dreadful" head injuries, while Mustafa's sternum and larynx had been fractured.
Younis received a life sentence with a minimum of 38 years in prison.