Forget the Diddy rumours, Sienna Miller is reportedly smitten with her The Edge of Love co-star, Matthew Rhys.

The pair were first linked in June after going on a date with co-star Keira Knightley and her boyfriend Rupert Friend - and Sienna is thought to have finished with Jamie Burke because of Matthew.

A source told the Sun: “This is the first bloke Sienna has been serious with since she finally split with Jude.”

“These allegations of her being with Diddy and splitting up his relationship with Kim Porter are awful. But they have actually worked in her and Matthew’s favour a bit. It has taken the heat off their relationship because people have been looking for a spark between her and Diddy.”

“Sienna and Diddy are party pals. They love to go out and have a good time but that’s where it ends, they have had some wild nights in Los Angeles, London and St Tropez but he isn’t someone she is going to take home to her mum.”

“Jamie Burke was just a distraction for Sienna. She was on the rebound and wanted some fun - and that’s what she and Jamie had. But now she wants more.”

And according to a source quoted in Cosmpolitan, Matthew is willing to step up to the task: “He is really into her but they have both been trying to keep it very quiet, only telling close friends.”

Matthew isn’t the first time that Sienna has found love in the workplace: she met Jude Law on the set of Alfie and is said to have had a fling with Daniel Craig after working together on Layer Cake.