A 30-year-old Wellington man accused of murdering a woman earlier this month has also been charged with sexual offending against her and a child found wounded at the scene.

A homicide investigation was launched earlier this month following the death of a 52-year-old woman at a Lemnos Ave property.

Police were alerted to the incident at around 1.10pm, and found the woman's body on arrival.

A seriously injured 12-year-old girl was found in the same bedroom as the woman's body.

The man accused of the murder has today had nine new charges laid against him, including charges he sexually violated the girl twice and indecently assaulted the woman by removing her under clothing.

He is also accused of entering a Lemnos Ave property on the day of the alleged killing with a steel mallet, with intent to commit an imprisonable offence.

The other charges are two counts of entering a building with intent to commit an imprisonable offence between February 9 and April 5, doing an indecent act on the girl by pressing his penis against her buttocks, impeding her breathing by blocking her nose and mouth, and wounding the child with the intent to cause grievous bodily harm.

He appeared in the Wellington District Court this morning and was remanded without plea to appear in the High Court at Wellington in June. He appeared in the High Court at Wellington earlier this morning, before the new charges had been laid.

He has not entered a plea to the murder charge.

The child has automatic name suppression due to her age and the sexual nature of the charges, and the woman has interim name suppression.

The defendant's name will remain secret for now, but will be argued in a name suppression hearing in the next few weeks.

Police have said they are not seeking anyone else in relation to the incident.

The man is alleged to have killed the victim between April 4 and 5.

Police said the accused lived on Lemnos Ave, and was known to the victims but was not related to them.

The two victims were found in an upstairs room. They did not live at the address but knew one of the occupants.