Lance Bass claims he has been "kept away" from Britney Spears for several years.
The 42-year-old singer is "definitely" a supporter of the 'Toxic' singer's bid to have her conservatorship withdrawn as although he hasn't seen his old friend for a long time, he's confident the 39-year-old pop star is "sane enough" to make her own decisions.
Speaking on the "Heather Dubrow's World" podcast, Lance said: "I haven't spoken to her for years. We've been kept away from each other for quite a while.
"I don't know exactly what she needs but I do know that she, to me — [from] what I see — is sane enough to pick her own people."
The "Circus" hitmaker has branded her conservatorship "abusive" and is particularly keen to have her father, Jamie Spears, removed from his position in control of her estate, a move which Bass particularly supports.
"I believe that she needs to be away from the dad. She needs to pick her own people running this conservatorship, if she even needs one, especially when choosing her lawyer."
The "Bye Bye Bye" singer is particularly concerned about the wider issues raised by Spears' continued conservatorship, which has been in place since 2008.
He added: "To me, there's a bigger picture here. … The main thing that I'm concerned about is the court systems and this judge. If this is really true, then we have to look at this judge, right? Because that means that they're corrupt. I don't know, it's scary."
Bass's *NSync bandmate, Justin Timberlake - who dated Spears from 1999 to 2002 - previously shared his support for the end of her conservatorship.
In a series of tweets after she spoke out in court last month, he wrote: "After what we saw today, we should all be supporting Britney at this time. Regardless of our past, good and bad, and no matter how long ago it was… what's happening to her is just not right.
"No woman should ever be restricted from making decisions about her own body.
"No one should EVER be held against their will … or ever have to ask permission to access everything they've worked so hard for."
Timberlake also shared the support of his wife Jessica Biel.
He tweeted: "Jess and I send our love, and our absolute support to Britney during this time. We hope the courts and her family make this right and let her live however she wants to live."