Pop star Beyonce Knowles has denied reports suggesting she is expecting second child with rapper husband Jay Z.

The 31-year-old singer posted a note online on Instagram and insisted "low life people who have nothing better to do than talk about me."

"I can't stop the rumours from starting, and I can't really change peoples minds who believe them, all I can do is sit back and laugh at these low life people who have nothing better to do than talk about me," she wrote.

The rumours about her pregnancy first began when Beyonce walked the red carpet at the Met Gala wearing a gown with a little bump, reported TMZ.

After that she cancelled her Mrs Carter Show performance in Antwerp, Belgium on the advise of doctors after suffering from dehydration and exhaustion.

She has a daughter Blue Ivy with husband Jay Z. Ivy  was born in January last year.
"I would like more children. I think my daughter needs some company. At some point, when it's supposed to happen," Beyonce had said once.