Former East 17 band member Brian Harvey has been arrested on suspicion of sending malicious communications.
The former singer was held at an address in Walthamstow after police were called to reports of a man threatening to harm himself.
Officers carried out a welfare check and arrested a man in his 40s, police said.
Following a health assessment at hospital, Harvey, 44, was taken into police custody.
Brian was the lead singer in popular 90s band East 17.
They sold millions of records, scoring several top 10 hits.
Harvey was injured in an incident in 2005 in an accident where he ran over himself.
