Kristin Davis, who plays Charlotte York, was seen filming a scene

It has been three years since the TV series, which followed the love lives of four professional women in New York, drew to a close.

BBC Radio 1's Heather Alexander spotted Kristin Davis, who plays Charlotte York, shooting a scene with Chris Noth, who plays Mr Big in the show.

Sarah Jessica Parker, Cynthia Nixon and Kim Cattrall are also taking part. The film is due to be released next year.

Heather Alexander said Charlotte's character appeared to be heavily pregnant.

All four of the TV show's main actresses will reunite in the movie

Fans may be surprised to learn she is expecting a baby as it was revealed in an earlier series that she would find it virtually impossible to conceive.

Speculation about supposed conflicts between the cast have previously been blamed for the delay in making the film.

Michael Patrick King, who executive produced the series, has written and is directing the film.

During its six-year run, Sex and the City won six Emmy awards and eight Golden Globes.

The conclusion of the show's plot showed Parker's character, Carrie Bradshaw, get back together with Mr Big.