A charge of attempted murder has been laid after an alleged home invasion in the Christchurch port of Lyttelton earlier this month.

A man in his 60s, who has interim name suppression, has been charged with grievous bodily harm after two people were injured in an alleged stabbing.

Police said they received a report of an assault at a residence on St Davids St in Lyttelton at 7.45pm on August 4.

"Two people are being treated, one of them for serious injuries, one of them for moderate injuries," police said.

The people involved in the incident were known to each other, police said.

A man was arrested at the scene and later appeared at Christchurch District Court charged with intending to cause grievous bodily harm to two people and using a pistol as a weapon.

At his first court appearance, he was granted interim name suppression. Other suppressions cover the case.

But today, new charges have been laid in court, including an allegation that he attempted to murder a man during the incident.

It's also alleged that he had six firearms with him at the Lyttelton house – a Ruger semi-automatic pistol, Smith and Wesson revolver, Sterling Model 300 handgun, Accelerator model handgun, Ruger revolver and a small silver handgun.

He's also been charged with unlawfully possessing a restricted weapon, namely a Maglite torch gun and two mag pen guns.

The case is scheduled to be called in court later this afternoon.