The film Renée Zellweger made when she was 'unrecognisable' is set for release

Renee Zellweger attends the World premiere of Bridget Jones's Baby at Odeon Leicester Square on September 5, 2016 in London, England. Photo / Getty

A newly-released trailer gives viewers a first glimpse at the film Renée Zellweger was shooting when speculation about her "unrecognisable" new look created a media frenzy.

Filmed more than two years ago, The Whole Truth tells the story of a teenage boy suspected of murdering his wealthy father - and a young lawyer determined to find out what really happened.

The trailer comes amid success for Zellweger's first film role in six years, in Bridget Jones's Baby, which opened atop the box office over the weekend in Australia and scored the biggest opening weekend for a romantic comedy ever in the UK.

Zellweger plays the mother of a teenager accused of murder in the film. Photo / YouTube

While the film will be released after Bridget Jones's Baby in most of the world, it was actually filmed more than a year beforehand: Shooting commenced on The Whole Truth in July 2014 - three months before Zellweger sparked intense media coverage with her "unrecognisable" appearance on an LA red carpet event.

Shooting for the third instalment in the Bridget Jones franchise began in October 2015.

Zellweger shot the film in 2014, at a time when media speculation about her looks was at its height. Photo / YouTube

Zellweger recently opened up about why exactly she'd quit acting for several years - and where she went.

Renee Zellweger Filming 'Bridget Jones'S Diary 2 ' In London's Borough Market. Photo / Getty

"I planned to take some time off after Chicago [2002], but there kept being once-in-a-lifetime experiences in front of me that I didn't want to miss out on," the 47-year-old explained in a recent interview with American Way Magazine.

"Then I learned you can't keep doing that forever, so I chose to see what would happen if I did let that once-in-a-lifetime experience that was ahead of me go and just be still and see what I could build."

Colin Firth, Rene Zellweger and Hugh Grant during Bridget Jones's Diary UK Premiere at Empire London in London, Great Britain. Photo / Getty

Zellweger, who travelled around South-East Asia and took up a college class during her time away from the spotlight, said she was happy she gave herself the chance to see more of the world.

"I think travelling off the beaten path is a good idea for anybody because it's essential for understanding not just the rest of the world but yourself," she says.