The body of James Grant was discovered in a flat in Kingsway Court in the Scotstoun area of Glasgow on 23 May.
The 59-year-old had not been seen for two weeks before his body was found. Relatives had informed Strathclyde Police when they were unable to contact him.
A police spokesman said a 47-year-old man has been arrested and detained in custody. A 41-year-old woman has also been detained by police in connection with the incident.
The man is due to appear at Glasgow Sheriff Court today.