Hand in hand: Sienna Miller and Rhys Ifans stroll through Paris

The pair, whose relationship continues to be the worst kept secret in showbiz, strolled hand-in-hand at the March aux Puces in the city, both wrapped up in black coats.

Welsh Notting Hill star Rhys wore a trilby hat and skinny scarf while Sienna stood out from the crowd in a bright blue head scarf.

The couple have been inseparable since August when Rhys moved into Sienna's London home. But they insisted they were "just good friends".

However, following a recent holiday to Mexico, friends believe Rhys will soon propose to Sienna, 26, who was once engaged to Jude Law.

They split after it was revealed he was having an affair with his former children's nanny.