The 1100cc bike was recovered from the Grand Canal at Bluebell yesterday afternoon following a tip-off.

The motorcycle had not been reported stolen and, following enquiries, it was learned that two men from Finglas had been stopped by gardai in possession of the vehicle last September.

A 28-year-old man told gardai that he was selling the bike to a 26-year-old friend and both men were arrested yesterday morning by detectives from Crumlin garda station.

They are not well known to gardai and are being questioned about the motorbike and also being asked to provide alibis for the day of the murder on 5 October.

Officers are studying CCTV footage in a bid to determine if the recovered motorbike was the same one used in the murder of Brian Downes and Eddie Ward. Gardai investigating the double murder believe that 'Border Fox' Dessie O'Hare, may have been involved.

Detectives say that former INLA leader O'Hare is now regarded as a suspect in the murders of Downes and Ward in Walkinstown last month.

Gardai have still not completely determined why Downes was targeted, but one line of inquiry being examined is that he was killed because he refused to pay a senior INLA figure in the capital protection money. Officers believe that the INLA figure may have contacted his friend O'Hare and asked him to "convince" Downes to pay up.

It is thought that the 40year-old car dealer also declined to pay O'Hare money and that the former terrorist decided to assassinate him without informing the INLA leader.

O'Hare, who was released under licence last year for the 1987 kidnap of Dublin dentist John O'Grady, has previously bragged that he personally carried out up to 30 murders during the Troubles.