Tina Arena discovers her heritage in Who Do You Think You Are?." link="/who-do-you-think-you-are-australia/show/78884/summary.html" target="_blank" loc="right">

Tina Arena says filming SBS's documentary series was so secretive, she had no idea what to expect.

It was a very long wait for Tina Arena between saying yes to SBS documentary series Who Do You Think You Are? and the commencement of filming.

But that's because producers took a long time to scour her family tree in Europe, in preparation for the singer embarking on an emotional journey.

"There was 18 months of research and apparently it hit a wall at some stage until some guy came out of the woodwork and started crossing the t's and dotting the i's with an extraordinary revelation," she says.

"But I take my hat off to that production company, they're Academy Award winners! The work that they do is beyond words."

The former Young Talent Time star had always felt confused about her identity since being the target of racism as a child. Her family had rarely spoken about where her Italian-born parents came from.

In the SBS series she will discover a lot more about their background as she travels to Sicily, seeking clues to many unanswered questions. The circumstances surrounding some family members will leave her with a lasting impact.

"I come from a pretty big family and a family that I have mutual respect for now -- not that I never did, but it takes something [like this] to be able to be liberated from whatever demon or question that you got an answer to. The whole journey answered probably most of my questions, which I think is a real privilege," she says.

Having become a mother herself in 2005, she now views her ancestry through new eyes.

"I think I would have still embraced it without having Gabriel, but there's something about giving life that does change you. It's a very difficult thing to intellectualise but giving life is probably the greatest gift we have as humans," she says.

Plans for the filming of Who Do You Think You Are? was so secretive that Arena was given no hints from producers about what lay in store.

"You know nothing. It's like working for the Secret Service where they say 'This is the kind of clothing that you need to prepare, and our passport and you'll get picked up and taken to the airport' -- and that's about all you know," she says.

"But you'll never get a great reaction if you know what's going on."

Who Do You Think You Are? airs 7:30pm Sundays on SBS ONE.