A father was taken to hospital by police weeks before he was found dead with his sister-in-law and two children.

Bartlomiej Kuczynski, 45, was found with a stab wound to his neck at a house in Costessey, near Norwich, on Friday.

Kanticha Sukpengpanao, 36, Jasmin Kuczynska, 12 and Natasha Kuczynska, eight, were found with stab wounds to their necks at the same property. Their deaths are being treated as murder.

We can confirm that the patient was taken to the emergency department by police on December 14. Following a comprehensive clinical assessment, the patient was assessed as having mental capacity and he left the unit before being reviewed again by the team

Mr Kuczynski’s death is not being treated as suspicious, and officers are not looking for anyone else in connection with the killings.

It has emerged that Mr Kuczynski was taken to the emergency department at Norfolk and Norwich University Hospital by police on December 14, the same day that a missing person report was filed from his home address.

He then left the unit after he was assessed as having “mental capacity”, the hospital said in a statement.

“We can confirm that the patient was taken to the emergency department by police on December 14,” a spokesperson for the hospital said.

“Following a comprehensive clinical assessment, the patient was assessed as having mental capacity and he left the unit before being reviewed again by the team.”

The four bodies were discovered by police at a house in Allan Bedford Crescent at around 7.15am on Friday after a 999 call from a member of the public.

Detectives said the man and two children lived at the address, but the woman was visiting and lived elsewhere.

A man had earlier called 999 from the property at around 6am that day, but police were not dispatched.

The incident has been referred to the Independent Office for Police Conduct (IOPC) due to the first 999 call on Friday, which did not result in the deployment of officers, and over police contact at the address on December 14, relating to the missing person inquiry.

On Tuesday, IOPC regional director Charmaine Arbouin said: “Norfolk Constabulary established that the man had made a 999 call to the force shortly before 6am on January 19.

“During that call, the man expressed concerns for his own mental state saying he was confused.

“He was advised to seek medical advice and police did not attend.

Following a mandatory referral from the force we have decided to investigate and will be examining if the force’s handling of the contact they had with the man was appropriate and in line with force policy, training and procedures

“At around 7am the force received a call from a dog walker concerned for the welfare of those within the home.

“Officers attended shortly after and, tragically, found the man, a woman and two children dead.

“Following a mandatory referral from the force we have decided to investigate and will be examining if the force’s handling of the contact they had with the man was appropriate and in line with force policy, training and procedures.”