As Beyonce’s marriage is hit by claims of trouble, did Solange accuse Jay Z of cheating with Rihanna in THAT elevator bust-up?

Footage of Beyonce's sister Solange Knowles viciously attacking her brother-in-law Jay Z in an elevator back in May fuelled reports that all was not well in the power couple's six year marriage. 

And now, a new report suggests that the row may in fact have been about the nature of Jay Z's relationship with his one-time protégé Rihanna. 

A source told New York Post's Page Six that Solange's elevator outburst came after she concluded the rapper was planning to meet Rihanna later at a club without wife Beyonce. 'Solange was like, "Enough is enough - you must be [screwing] Rihanna,"' the insider said. 

They then added: 'To many people who know them, they know it’s not out of the realm of possibility.'

Perhaps aware of the rumours, Beyonce ensured she posted an Instagram image showing she and Rihanna posing together after the Met Gala.  

Rihanna and Beyonce have long been the subject of a supposed rivalry, with the Crazy In Love singer giving a somewhat cryptic response when asked about the Barbados-born star back in 2011.

'There is room on this earth for many queens. I have an authentic, God-given talent, drive, and longevity that will always separate me from everyone else,' she told Complex magazine.

'I’ve been fortunate to accomplish things that the younger generation of queens dream of accomplishing. I have no desire for anyone else’s throne. I am very comfortable in the throne I’ve been building for the past 15 years.'

Meanwhile, additional sources told the newspaper that it is not a matter of if but how Beyonce and Jay Z will split.

Currently the only time they spend together is on their joint On The Run tour where the newspaper alleges they are travelling with marriage counsellors.