A court has heard how a man hid his girlfriend under the floorboards, and then constructed an elaborate plan to cover his tracks.
Stephen Devesey from Birmingham is accused of the murder of 18-year-old Nicole Cartmell.
The prosecution described Devesey as a "cunning and clever" killer, alleging he murdered Miss Cartmell almost three weeks before her decomposing body was found at his terraced home in Handsworth, Birmingham. The jury heard that Devesey had repeatedly lied to police, as well as Miss Cartmell's mother and others about her whereabouts.
Timothy Barnes QC, prosecuting, told the court that Devesey killed Miss Cartmell by asphyxiating her shortly after she made a "frightened" 999 call on February 10 last year. "What caused him to kill her on that day we do not know.
"When he had killed her, the defendant prised up some floorboards in the front room of his address and dropped the body into the cellar some 7ft below.
"He covered the body with layers of clothing and rubbish and there over successive weeks the body decomposed, giving rise to unpleasant smells which the defendant tried to mask with the aid of incense sticks."
The court also heard allegations that Devesey used the victim's bank card on four occasions between her death and the discovery of her body on March 2 last year.
Days after the alleged murder, Devesey is also said to have flirted with a woman on Facebook, changing his relationship status from "engaged" to "its complicated"
The jury heard that Devesey told "persistent lies" to try to distance himself from Miss Cartmell's death.
"The Crown say he acted from the outset in a calculating and devious manner designed to allay the suspicions of those who wanted to know where Nicky was, and concerned to cover up the enormity of what he himself had done." Mr Barnes QC told the court.
Devesey denies murder and the case continues at Birmingham Crown Court.