A father with 'a heart of gold' bled to death on a riverside bench after accidentally falling asleep against a knife in his rucksack, an inquest heard.

The death of Robert Brown, 57, sparked a large-scale murder investigation after he was found slumped on a bench beside a canal footpath in Northampton last summer.

He had last been seen visiting a supermarket the previous day before being discovered by a passing cyclist who noticed blood dripping through the gaps in the seat.

The grim discovery at around 6.30am on August 1 last year triggered a huge police response amid fears he had been deliberately killed.

Detectives launched extensive searches of the River Nene and arrested three people on suspicion of murder. But all were later released without charge.

An inquest heard on Thursday how Mr Brown's death was most likely the result of a freak accident after he drunkenly 'rolled onto a knife carried in his backpack'.

The hearing was told Mr Brown may have fallen into a deep sleep, putting his weight onto the rucksack which led to the knife penetrating the bag.

The single-edged five inch (13cm) blade cut through the bag and all three layers of his coat before slashing his arm resulting in catastrophic blood loss from a 3cm wound.

Detectives dropped the murder investigation in February this year and officers concluded the injury sustained is 'likely to have been unintentionally self-inflicted'.

Northamptonshire senior coroner Anne Pember said in her view the case was a 'tragic accident.'

Detective Chief Inspector Torie Harrison, of Northamptonshire Police, said they initially thought Mr Brown had been killed by a third party and the weapon had not been located, or it was accidental death or self-harm.

The inquest heard Mr Brown, who struggled with alcohol dependency, had suffered a slash wound from a blade, but it did not hit any arteries.

There was no blood on the knife, but fibres on the blade matched layers of his coat and traces containing a high amount of his DNA were identified.

The police report said the findings support that the knife which caused the damage belonged to the victim.

Officers said there was no motive for anyone to murder Robert and DCI Harrison said she believed it was a 'tragic accidental death'.

A post-mortem examination had given a provisional cause of death as acute blood loss from a wound to his left upper arm.

At the time of his death his grieving family paid a moving tribute and described Mr Brown, who was also a grandfather, as having 'the gift of the gab and a heart of gold'.

His parents and brothers said in a statement: 'Rob was quite a character and always full of fun.

'He was our real-life Peter Pan - the boy who never grew up. Everyone who knew Rob just loved him.

'He definitely had the gift of the gab and could talk the hind legs off a donkey.

'We would joke that he knew more about everybody else's business than his own, but that was Rob. He had a heart of gold and was always ready to help others.'

Son Daniel, daughter Tonia, and his grandchildren also paid tribute and said: 'Our hearts are broken, but everyone's kind words bring us comfort and show how much of an impact our dad had on the people he met.

'He loved to talk to anyone and everyone! We have our happy memories to cherish, and Dad will leave a massive gap in our family with his cheeky smile and kind heart.

'Dad was a kind and loving man, and we will all miss him incredibly.'

His partner Julia said: 'At school I always had the hots for Robert, he was the school heartthrob.

'Being with Robert there was never a dull moment, we laughed and joked at the same things.

'He would do anything for me, he was a selfless person and always put others first, nothing was ever too much.

'I'll hold on to our laughter and adventures. You may be gone, but your love, kindness, and spirit will live on in me.'

The coroner recorded a verdict of accidental death.