An Oamaru man plunged a syringe needle into his own eye socket and threatened to kill police officers as he sprayed blood around the cell from a cut in his arm, according to court documents.

Mark John Sheridan, 29, appeared in Oamaru District Court yesterday charged with common assault, possessing an offensive weapon and threatening to kill, the Oamaru Mail reported.

The police summary of facts said that on August 24 Sheridan was arrested after a confrontation with a person living with his former partner.

At the police station Sheridan put into a holding cell and "began to smash his head at the glass wall, time and again".

Police said he did this an estimated 30 times before "faking unconsciousness" on the floor.

He then took a syringe he had with him and plunged the needle into his right forearm, drawing blood.

He held it up at head-height with the needle facing police staff, threatening and challenging the police to enter the cell.

Blood from his arm sprayed about the walls and floor of the cell.

He then pretended to stab the needle into his eye in an attempt to lure police inside.

"When this did not work, he then plunged the needle into his right eye socket and continued to challenge police," police said.

Officers entered the cell, armed with a Taser, pleading with the defendant to drop the needle, which by this time was imbedded into his eye socket and being held there with one hand.

Sheridan was tasered and the syringe was removed when he had been subdued.

While being handcuffed the defendant kicked, swore, verbally abused and resisted police, who said he spat at officers and attempted to bite their fingers, saying he would "infect them".

None of the officers was injured.

The court was told Sheridan had apologised for his actions at Oamaru Police Station

Judge Stephen O'Driscoll convicted and remanded him to appear in the Dunedin District Court on October 5.