A making-of behind the scenes TV documentary special about the making of this movie was made by the BBC and called "Carry on Forever" [See: Film Night: Carry on Forever (1970)] being first broadcast on TV around the time that the picture launched in theaters.
Actor Bernard Bresslaw portraying Upsidaisi appeared in black-face make-up something which now today by modern standards is now considered racist and controversial.
After Chumley falls out of the tree, when the scene switches to night, Upsidasi says something to a native before putting something in the cooking pot. His mouth continues moving after he's finished speaking.
When June discovers the jungle lake, the water is clean and
clear. But when she and Jungle Boy get into it, the water looks contaminated with patches of foam.