A third person has been arrested in connection with the murder of a man at a west London house where an empty grave was found in the garden.
Zbigniew Michniewicz, 36, of Greenford Road, Greenford, was found inside the house where he lived, on 5 December.
Officers found the grave on the same day and arrested a 17-year-old girl and 20-year-old man on suspicion of murder. They have both been released on bail.
A 45-year-old man was held on Sunday and remains in custody.
A post-mortem examination has taken place but police have not revealed the cause of death.
Police are asking for neighbours who may have seen something suspicious taking place in the garden to contact them.
They also want to hear from anyone who saw a fight between three men outside 251 Greenford Road on an evening three or four weeks ago to come forward.
A man, 20, has been charged with conspiring to prevent the lawful and decent burial of a body and has appeared before magistrates.