A man has been shot dead at a house in Salford, in what police say was “a targeted attack”.
The victim was Paul Massey, a local businessman and former mayoral candidate, the BBC understands.
Mr Massey stood unsuccessfully to be mayor of Salford in 2012.
Greater Manchester Police said a 55-year-old man had died of gunshot wounds in the Clifton area. They said there had been several reports of gunfire at about 19:30 BST on Sunday.
The victim has not yet been formally identified.
Security has been stepped up in the area of the shooting, which happened in Manchester Road, and police said the road was expected to be closed until Monday.
Det Ch Supt Russ Jackson said: “People will understandably be alarmed when they hear about this incident, which we believe was a targeted attack.
“I would like to reassure the public that we have a heightened level of police officers in the area while we establish the full circumstances of the incident and identify those responsible.
“We are actively following a number of lines of inquiry, however I would urge the local community to come forward if they saw or heard anything in the area.
“I want to stress that any information received will be treated in the strictest confidence.”
Mr Massey was jailed in 1999 for stabbing a man outside a nightclub.
Standing as an independent candidate in the May 2012 mayoral election, he received 1,995 votes – 4.45% of the poll – and came seventh out of 10 candidates.
Mr Massey had said in a BBC Radio Manchester debate he would do the job of mayor without being paid, saying: “I will do it for free; I will do it for the voice of the people.”
The previous year he had been arrested in a money laundering investigation but was not charged.