Police on Tuesday said a 51-year-old woman was arrested in Tuen Mun on suspicion of murdering her 63-year-old husband.

Officers responded to a report at 6.41pm on Monday of an unconscious man inside a house in Tseng Tau Chung Tsuen.

They found the man with severe head injuries and he was pronounced dead at the scene.

Also present were the man's wife and their 24-year-old daughter, a student who made the emergency call.

The wife reported feeling unwell - experiencing dizziness and vomiting - and was taken by officers to Tuen Mun Hospital for treatment.

Chief Inspector Chong Yuen-na said the couple had lived at the address for more than 20 years.

She said the deceased worked was a cleaner, while his wife was unemployed.

"Their long-term relationship was reportedly very strained. They were also facing severe economic difficulties, which led to frequent disputes," Chong said.

Police believe the alleged attack occurred in the early hours of Monday morning, with the daughter reporting she found her father lying on a bed with head wounds when she returned from her studies at around 6pm.

Investigators recovered a potential murder weapon at the scene - a stainless steel cooking pot roughly 19 centimetres in diameter.

The exact cause of the man's death awaits further examination.