The classic car is due to be sold by auction during a historic motor race meeting at the Goodwood Revival in Britain on September 16.
Auctioneers, Bonhams, have estimated that the car should fetch between £250,000 and £300,000 (€286,000-€343,000). The actual car which featured in the 007 film Goldfinger fetched over $4.1m when sold in the US last year.
Filan’s model, which was manufactured in 1964, was discovered in Malaysia by marque specialist Desmond J Smail and was in need of full restoration.
Mr Smail re-imported the car to Britain and sold it on to the Westlife star.
He restored the Aston Martin to Filan’s own specifications in a project that took almost three years to complete, as it required a full body rebuild as well as a full engine rebuild to restore its original 4.2-litres capacity.
Filan also had the car fitted with air conditioning and a hi-tech Sony stereo system.
Shane has described himself as “car mad” and said he bought the DB5 as a 30th birthday present for himself because it was something he had always wanted.
However, the 32-year-old has only managed to drive just over 400 miles in his Aston Martin in the past two years since the car was fully restored.
It is understood the singer has decided to sell the vintage model as Westlife will be on tour for the next 12 months.
“This car represents a wonderful opportunity to buy an ‘as new’ Aston with all important provenance,” said Bonham’s spokesman, Tim Schofield.
The proceeds of the sale will also provide a major cash boost for the singer. Filan’s foray into business outside the music industry has suffered a number of setbacks in recent years, with his Sligo-based property development company, Shafin Developments, recording accumulated losses of €3m this year.