The body of 55-year-old Francis McGrow was discovered at about 10am on Sunday October 27 in his flat in Hermiston Road in the Springboig area of Glasgow.
A murder investigation was launched after a post-mortem examination was carried out.
The man has been detained in police custody and is due to appear at Glasgow Sheriff Court.
Millionaire crime boss Tam McGraw died from a heart attack at his Glasgow home in 2007.
Known as The Licensee, he was a feared member of the city's underworld with links to drug trafficking and extortion.
The brothers have different names because Tam changed his from McGrow to McGraw, police have said.