GEORGE TOWN: Police seized four pistols, ammunition and drugs in a raid on a house in Taman Idaman, Simpang Ampat, near here early yesterday.
Police believe the guns were used in crimes on the island and other states.
They detained a married couple and their adopted sister in connection with the case.
The suspects, aged 33, 38 and 59, were picked up about 3am.
Bukit Aman Narcotics CID director Mohmad Salleh said the suspects might have used the firearms, together with handcuffs, to impersonate enforcement personnel.
The semi-automatic pistols comprised a Baretta, Colt MFG, Compact Cz 75D and Cz 2075.
Also seized were 151 rounds of ammunition and three pairs of handcuffs.
Police also recovered 573.9g of heroin and 26.7g of ketamine, worth about RM11,500.
Mohmad said the male suspect was previously detained under the Prevention of Crime Act (Amendment) Act 2017.