American singer and songwriter Beyonce Knowles is allegedly upset with husband Jay Z after aspiring rapper Rymir Satterthwaite claimed he is his father.

Last month, the 21-year-old alleged in a New Jersey court that his mother Wanda Satterthwaite had an affair with the 45-year-old rap mogul, whose real name is Shawn Corey Carter, in the 1990s and got her pregnant.

Adding on, the suit also alleges that Jay Z has been avoiding a paternity test for the past four years.

According to Grazia magazine, the 33-year-old Halo singer is not happy with the allegations.

"Beyonce is a mess right now. She's furious that she's been put in this position once again. It's one rumour after the next. Jay Z says it's not true, but she seems to feel humiliated and under a lot of strain. She's not in a good place," a source said.

"Beyonce feels overwhelmed and embarrassed. She's fiercely protective of her family and wants to preserve the image of her picture-perfect marriage. It's important that Jay Z takes a paternity test to prove this latest rumour wrong so they can draw a line under it," the insider revealed.

The source said that even if Jay Z agrees to the test, the couple's marriage will not be the same like before.

"Beyonce and Jay Z have been keeping it together in front of fans, but it's getting harder. She's doing everything she can to make this right, but deep down Beyonce knows that whether or not Jay agrees to these tests, their marriage is going to be forever tarnished. Everyone is really worried for her and are unsure how much longer she can go on like this," the insider said.

Reports of the Grammy Award-winning singer and Jay Z's troubled marriage have been doing the rounds for some time now.

Last year in May, during the Met Gala after party at New York City's Standard Hotel, Jay Z's closeness with designer Rachel Roy allegedly provoked his sister-in-law, Solange, to fly into a rage. Footage of Solange physically attacking Jay Z in an elevator at the hotel emerged soon after.