According to sources, Harry, 29, recently confided in friends that things were not going well with Cressida, 24.
Speaking to British newspaper The Telegraph a source said: "It is virtually impossible to have a successful romance and relationship in the full glare of the world’s media."
Prince Harry and Cressida Bonas have split after nearly two years
When asked if they may reunite, the source added: "It’s impossible to say because I don’t think the two of them know either."
In a similar fashion to how the Duke and Duchess of Cambridge split for some months in 2007, the source also suggested that the two have "paused for a breather".
The couple, who met through Princess Eugenie, have kept their relationship private, but in recent months they have been seen out and about together.
In early March, Cressida joined Harry at a very public event, supporting him at the launch of the very first WE Day at Wembley Arena.
Later that month Prince Harry whisked her away for a short skiing holiday in Kazakhstan.
Prince Harry and Cressida were spotted at a rugby match in March 2014
The couple flew by helicopter to the exclusive resort of Shymbulak, a luxury chalet located in the mountains above the city of Almaty.
Speculation then began to mount that the Prince was on the brink of proposing to Cressida, and as a result, the odds for Harry popping the question were cut to only 8:1, according to betting firm Ladbrokes.
It was also thought that the blonde beauty, who recently completed a postgraduate program in dance studies at London's Trinity Laban Conservatoire of Music and Dance, was going to attend the wedding of Guy Pelly in America, a close friend of Princes William and Harry.
Cressida recently moved to Shepherd's Bush, west London which is only two tube stops away from Kensington Palace.
On Tuesday Prince Harry met with some of the wounded servicemen and women hoping to take part in his Paralympic-style sporting event, the Invictus Games, during a visit to Tedworth House on Tuesday, while it was also confirmed that he was gearing up to host a fun-filled 10th birthday party for his charity Sentable.