A 3-year-old was left covered in blood and bleeding from his mouth and nose following an alleged attack by a Mongrel Mob member on the boy's dad in a Hastings park yesterday afternoon. 

A source told the Herald the boy was on a swing when the gang member screamed at the toddler's father and the boy's mum, who is heavily pregnant, to leave Cornwall Park. 

The 20-year-old dad went to grab his son off the swing, and it is then that the Herald understands the child was hit in the face, as he was being held by his dad. 

The source said the gang member then continued screaming at the parents, even after injuring the child. 

Other people at the park filmed the incident. 

Photos obtained by the Herald show the child covered in blood and bleeding from the mouth and nose. 

In one of the photos, it appears to be from the boy's 21-year-old mother, who wrote in a caption: "So pregnant 'n' helpless. So just to know when I go to police it ain't snitching it's called protecting what's mine." 

Another photo's caption reads: "I wish I could have done more my son. My heart ain't never been broken [like] this before! A grown man put his hands on my baby." 

In a third photo the caption said: "How could you continue to want to fight after seeing what you did to a child's face?" 

The Herald has also been given a video of what appears to have unfolded after the initial incident. 

The source said the parents took the boy to a GP, and to the Hastings Police Station yesterday. 

The source also told the Herald the Mongrel Mob leaders were not impressed with what they had seen and heard of the incident. 

"There's a number of things that can happen from here," the source said. "That member could be de-patched." 

The Herald has decided not to name the whānau involved or the gang member for legal reasons. 

Police yesterday made a public appeal for anyone with photos, video or information about Wednesday's incident to come forward. 

Hastings Police today confirmed they are investigating an incident at Cornwall Park yesterday where a young child was allegedly assaulted. 

"Police are currently wanting to speak to any witnesses that may have seen the incident," a statement reads. 

Information can be provided via 105, quoting file number 220601/5431. 

Alternatively, information can be provided anonymously via Crime Stoppers on 0800 555 111. 

- by Joseph Los'e, NZ Herald