A £70,000 reward has been offered in the hunt for two valuable LS Lowry paintings stolen by an armed gang.
The Viaduct is the most valuable of the works taken
The Viaduct and Tanker Entering The Tyne were among five works taken during a raid at an art collector's home in Cheadle Hulme, Stockport, last month.
Three men, armed with knives, tied up Ivan Aird and threatened his wife and two-year-old daughter.
Police said the community was outraged by their ordeal and hoped the reward would yield new information.
The five artworks, valued at more than £1.5m in total, and Lowry's palette and brushes were taken on the morning of 3 May.
The Surgery pencil sketch is worth an estimated £38,000
Insurance company AXA has offered the reward specifically for the recovery of The Viaduct - valued at about £700,000 - and The Tanker Entering The Tyne, which is worth between £500,000 and £600,000.
Louise Aird, 40, let the gang in to the house at Brackenwood Drive thinking it was a post delivery.
Police said that the men threatened Mrs Aird and her daughter Sabrina, who she was holding at the time.
Det Supt Tony Cook, of Greater Manchester Police, said: "People have been outraged that these criminals were not only able to go into Ivan and Louise's home, but also threaten them and their daughter.
"The stolen paintings are not only extremely valuable but also hold a great deal of sentimental value for Mr Aird, as Mr Lowry was a close family friend."
Mr Cook said the paintings were also a major part of the heritage of the region and would be almost impossible to sell.