Heroin was found hidden in a Kinder Suprise during a police raid.
Norfolk Police discovered the drug in the chocolate egg, which includes an inner plastic holder for a toy, at a flat in The Maltings, Dereham, on 7 September.
As reported in the Eastern Daily Press, a man and a woman have been questioned and released under investigation.
Insp Jon Papworth said: "We have carried out several raids in recent months and will continue to do so."
Drug gangs have been targeting Dereham and other market towns as they look for new gaps in the market, following high profile arrests in other areas, Insp Papworth said.
"We are working with housing associations, who have been very good at sending out warnings and getting people evicted, where necessary," he said.
"Everyone has a role to play in the fight against drugs."
Police said a "small" amount of the drug had been found in the egg.