18 May, 11:09
IRFU Chief Executive Philip Browne has issued a statement following confirmation of Ronan O'Gara's decision to retire from playing professional rugby.
Duffy, twice capped by Ireland, and fellow Irishmen Gavin Simon Keogh and Mel Keane will remain at the Stoop despite 'Quins being relegated to the National Division One last month.
Former Munster full-back/fly-half Jeremy Staunton has, however, been released from his contract despite having a full year still to run on the deal.
The 25-year-old Staunton had started 22 times for 'Quins, who have signed Dean Richards as their new director of rugby, this past season, scoring 217 points in the process.
Quins chief executive Mark Evans told the club's website: "The response we've had from the squad has been magnificent and I'm sure the news about which players are staying will be a tremendous fillip for everyone associated with the club.
"Given the loyalty the players have shown and the talent that as a group they possess, I'm very confident that we can achieve our aim of returning to the Premiership at the first attempt."