Bynes' bizarre behaviour has made her a regular in the headlines over the last few months, with many fans growing concerned for the star's mental health due to her strange rants on Twitter.com.
MCCarthy stepped up gossip about the Hairspray actress on Wednesday by suggesting police were called to deal with drama at Bynes' New York home on Wednesday.
She tweeted, "Police are at Amanda Bynes' house. I hope they get her help. Enough of this circus. She needs help," before adding, "It came from a publicist but if no one can back it up it could be wrong."
MCCarthy revealed a publicist named Jonathan Jaxson sparked the rumours and posted a screen grab of his tweets, which suggested police had been called to the star's home to deal with an emergency.