Gardai have reportedly established that the knife used to kill Sebastian Creane in Bray at the weekend was bought by Shane Clancy just an hour before the stabbing.

Reports this morning say Mr Clancy offered to drop Mr Creane home to his house in Bray in the early hours of Sunday morning following a night out in Dalkey.

The 22-year-old Trinity College student then drove to a 24-hour shop and purchased a block of knives before driving back to the house around an hour later.

At this stage, Mr Creane's girlfriend, Jennifer Hannigan, had arrived at the house from a night out with her own friends.

Gardai say it is unclear if Mr Clancy forced his way into the house or rang the doorbell before stabbing Sebastian Creane to death with one of the knives.

Ms Hannigan was also stabbed in the back during the attack, while Sebastian's brother Dylan was stabbed eight times.

They both survived and are recovering in hospital.

Mr Clancy subsequently went to the back garden of the house and stabbed himself in the heart.

Gardai say they believe the attack was planned and Clancy, who had previously been in a relationship with Ms Hannigan, carried out the stabbings out of jealousy.