It can now be reported the man sentenced for throwing muck over Gerry Brownlee was previously convicted of possessing a large amount of child pornography.

41-year-old John Andrew Howland has been sentenced to 80 hours community work after he threw an ice cream container of ingredients over the Earthquake Recovery Minister, at last month's five-year earthquake memorial service.

He lost his son Jayden in the 2011 earthquake.

In 2013, Howland was sentenced to eight months' home detention after being caught with thousands of images of child pornography on his computer. 

At the time he said depression triggered by his teenage son's death was behind his descent into the world of child pornography.

John Howland poured brown sludge over Earthquake Recovery Minister Gerry Brownlee at last month's five-year earthquake memorial service. Photo / Kurt Bayer