Pop diva Rihanna and Hollywood celebrity Leonardo DiCaprio - a match made in heaven?

New pictures of the couple just emerged on online gossip website TMZ, showing the two getting cozy at Rihanna's recent birthday bash, which DiCaprio is said to have helped organise.

The blurred picture shows Rihanna lighting what seems to be a birthday candle, with the bearded Titanic star standing behind her, holding what appears to be a shot glass.

According to TMZ, the couple engaged in "plenty of PDA" (public displays of affection).

Online reports say romance rumours about the couple have been going around for months after they were spotted together at several parties, but some allege the relationship is not exclusive.