Police said a murder investigation was underway after the death of the 22-year-old woman at the Sirhowy Arms Hotel in the village of Argoed in south Wales, but did not specify the nature of her injuries.
The BBC reported that she was “murdered in an act of cannibalism”, and had been in a relationship with the 34-year-old suspect.
Officers were called to the hotel, which also operates as a hostel for homeless people, at around 1:30am (0130 GMT) after receiving a report that a man was attacking a woman.
“The woman, aged 22 from Blackwood, was located with injuries and was pronounced deceased at the scene,” said a statement from Gwent Police.
“A Taser was discharged and a man was arrested… Whilst under arrest, the man became unresponsive.”
The man was given first aid but was later pronounced dead. Police described him as a local man.
Local councillor Leon Gardiner said Argoed was in a state of shock.
“This has hit the community for six,” Gardiner said.
“I have lived here and represented Argoed for over 30 years and this is the worst tragedy that has happened for us as a village.”
Once a popular pub, the Sirhowy Arms was converted into a Bed and Breakfast and was used by the council to temporarily house homeless people.
Some villagers said there had previously been trouble at the hostel, the BBC reported.
The death of the suspect after he was Tasered is unusual for Britain.
A spokeswoman for the Association of Chief Police Officers (Acpo) said that up until now, there have been no deaths attributable to Taser use recorded in the UK.
“There have been deaths where Taser has been used, but inquests have revealed these people have died from other injuries or reasons,” Acpo said on its website.
British police started using Tasers in 2004 and their use by specially trained officers is increasing, according to the Association of Chief Police Officers (Acpo).
The case has been referred to the Independent Police Complaints Commission (IPCC), which handles complaints against the police- AFP