Lily Allen has sparked rumours that she is pregnant after an appearance at Glastonbury.

The 25-year-old star, who announced her retirement from the music industry in February, stirred up speculation after wearing a figure-covering poncho and only drinking soft drinks during the exclusive Playstation 3 Singstar event at the festival.

The Sun claims that the singer also refused to be photographed at the event and left after just half an hour, claiming to be “tired”.

A source at the party said: “Lily’s ­behaviour was just so out of­ ­character. Everyone was gossiping that Lily must be ­pregnant. It was the talk of the party.”

Allen told last month of her intention to have a baby with long-term partner Sam Cooper “within the year”. She suffered a miscarriage in 2008 after falling pregnant by former boyfriend and Chemical Brothers star Ed Simons.