The accused's wife had died 15 years ago, police said. (Representational)

A man who allegedly sexually assaulted his 19-year-old daughter for two years and later killed her was arrested in Gorakhpur, police said on Saturday.

He was arrested on Friday following the complaint by the woman's elder sister, they said.

Police said the man raped his younger daughter several times in the last two years and killed her by cutting her neck on the night of July 26.

He buried the severed head in the Urwa area and threw the lower part of the body in a nullah, they said.

"During interrogation, the accused told police that he was raping his daughter for the last two and also killed her," Senior Superintendent of Police Sunil Gupta.

His wife had died 15 years ago, he added.

The man's elder daughter got married in 2015 and he was living with his younger daughter, police said.

"When the younger daughter resisted her father's attempts to sexually assault her, he killed her," they said.

The elder sister grew suspicious when the younger sister did not visit her on Raksha Bandhan. When she enquired about it from her father, he told her that he killed the younger daughter, police said.

The elder sister daughter then approached police, they said.

"Police have recovered the body parts. A case of murder and rape has been registered against the man and he has been sent to jail," Gupta said.