Former chart star Brian Harvey has been arrested on suspicion of sending malicious tweets.
The ex-East 17 singer, 43, has been taken to a police station in north London.
Harvey appeared on TV show I'm A Celebrity... Get Me Out Of Here! in 2004.
Former boyband East 17 sold millions of records and enjoyed several top 10 singles. But Harvey's remarks about Ecstasy saw him sacked from the group.
He was left with severe injuries in 2005 following an accident in which he ran over himself.