Alan Pardew's side are considering moves for the out-of-favour Manchester City defender and Netherlands international with the France full-back on the verge of leaving the club
Debuchy completed a medical on Monday ahead of finalising a switch to Emirates Stadium, where he will replace Bacary Sagna following the Frenchman's switch to Manchester City on a free transfer.
Alan Pardew is reluctant to see Debuchy leave without having a suitable replacement right-back lined up, however, with out-of-favour Manchester City star Richards high on the list.
The Magpies have had a long-standing interest in the 26-year-old and were considering moving for the versatilse defender as early as March.
And Debuchy's impending exit to join up with Arsene Wenger at Arsenal has accelerated Newcastle's desire to conclude a deal, with the France international one of their most consistent performers since joining from Lille back in January 2013.
Feyenoord right-back Janmaat is also on Pardew's radar and is considered the cheaper option, with Richards still expected to command a significant figure in transfer fees and wages, despite his injury struggles.
Janmaat's impressive performances at the World Cup with Netherlands have reportedly attracted interest from Manchester United, although the Newcastle hierarchy are confident that they would be in a position to lure him to St James' Park.
The signing of Richards or Janmaat would represent Newcastle's second significant signing of the summer transfer window, with Siem de Jong having already completed his switch from Dutch champions Ajax.