A lawyer has been questioned about an alleged conspiracy to pervert the course of justice in relation to the 2009 murder of Mohammed Haddara.

The lawyer, who had represented members of the Chaouk family, the arch enemy of the Haddaras, was arrested by homicide squad detectives at his Fairfield home about 7am on Friday.

Mohammed Haddara was fatally shot at the front of his parents' home in Altona North. Credit:Ten News

The 67-year-old was released without charge several hours later. Police said inquiries were continuing, but the lawyer denied any involvement in the alleged conspiracy.

He is not suspected of any involvement in the slaying of Mr Haddara, a member of the western suburbs crime family, who was fatally shot in front of his parents' home in Altona North on June 20, 2009.