Rihanna thinks Justin Timberlake is a songwriting "genius".

The pop beauty collaborated with the 'SexyBack' singer on hit single 'Rehab' and Rihanna admits she learnt a lot from him in the studio.

She said: "Working with Justin in the studio is just great. He's a fun guy and likes to make all the sessions enjoyable. He's also such a genius when it comes to lyrics."

Rihanna has also learnt a lot about music and life in general from her mentor Jay-Z - who signed her to Def Jam Recordings when he was label president.

She added: "From Jay-Z I've also learned a lot. He is more of a mentor in general - not just for music but he gives good all-round advice."

The 22-year-old singer is currently on the European leg of her 'Last Girl on Earth' tour.

The run of shows are her most ambitious yet and feature a number of costume changes and rigorous dance routines.

She previously said: "We've never done a tour to this capacity. The production is unbelievable and so are the costumes, we just took it to a whole new level. We just keep growing."