Beyonce Knowles and Jay-Z may buy Ricky Martin's Miami Beach mansion.

The superstar couple - who are expecting their first child - went house hunting in Florida last week where they viewed Ricky's $12.5 million, ocean-front mansion with an estate agent although it is unclear if they will make an offer, according to gossip website TMZ.

The seven bedroom, 10 bathroom palatial home also includes a swimming pool and was originally bought by Ricky for $10 million in 2005.

Beyonce and Jay-Z already own an apartment in New York City and are thought to be preparing a huge nursery for their little one.

A source told Us Weekly their home "will have a nursery that is 2,200 square feet".

But some of the couple's friends are not too keen about the idea of creating such a big space for their tot to play in.

The insider added: "Some people are like, 'Won't you be scared to leave your baby in that huge room?' "

Beyonce has no concerns about her forthcoming step into motherhood and she recently revealed her pregnancy is "going really well".

She explained: "It's going really well, I am so happy with everything right now.

"I am not nervous because I know it's happening at the right time. I felt I got married at the right time for me, and now we are having the baby at the right time. I feel like we didn't rush anything, and now we are being blessed with everything naturally."