Former *NSYNC star Lance Bass has responded to harsh tweets directed at him by actress Amanda Bynes.

After Bass expressed concern for the star during an interview, Bynes took to Twitter and hit out at her former friend saying: "I ignored Lance Bass on twitter and now he is saying I have a mental illness. Sorry you're an ugly ex boy band member w/ no talent or career. I haven't spoken to Lance Bass in 11 years. To say I have a mental illness out of nowhere makes me lash out! You're making me crazy!"

Bass appears to find it hard to believe that the comments were real, seeing as the pair once worked together and were quite friendly. In response to the tongue lashing, Bass posted: "Ouch - The Amanda I know would never had said something like this to me - either this is a fake person or she really does have a mental illness. Way too sad. I reached out - all I can do."

Bass also addressed Bynes’ claims of 11 years of silence between them by adding: "Now I really don't think this is Amanda - we shot ‘Love Wrecked’ together 7 years ago and she was just at my bday party 3 years ago. Hmmm 11?"

In another radio interview Bass also claimed that the former Nickelodeon actress has cut herself off from friends and family.

“She deleted all of her email addresses and cell phone numbers so none of her friends can get in touch with her,” said Bass to SiriusXM. "Everything is deleted. She obviously has a cell [phone]… She's tweeting, but none of her friends can get to her. Her family can't get to her… so the only way into her life is through Twitter."

Watch the trailer for ‘Love Wrecked’ below: