Two men who allegedly forced a teenager to eat red-hot bongo chilies have been charged with assault in New Zealand.

Local police did not detail the alleged crimes but the victim, an 18-year-old young man who cannot be named for legal reasons, recounted his ordeal to Fairfax New Zealand earlier this month.

He claimed a group of men assaulted him in a basement after an argument over a prank telephone call, punching him and forcing him to eat bongo chili peppers.

The chilies, cultivated in Fiji, reportedly measure 100,000 to 350,000 Scoville heat units, compared to 3,500 to 8,000 for a jalapeno.

The youth said he ate one but could not finish a second and was punished with a punch in the head.

"My insides were hurting, sweating, and I couldn't see anything or even talk properly," he said.

"Everyone was just laughing and watching."

He said a man then pulled down his pants and grabbed his genitals. Police launched an investigation after he told his mother about the alleged sexual assault the next day.

Two men, aged 24 and 29, were due to appear in Hamilton District Court in the North Island, acting detective Sergeant Paul Van der Zee said.

"The offenders have been charged with injuring with intent to injure, common assault and indecent assault," he said in statement.