A former ship captain, his wife and the man's sister have been detained in connection with the murder of a 'bomoh' in Section 8, Kota Damansara last Friday.

The 43-year-old man and his 41-year-old wife, a secondary school teacher, were nabbed on Tuesday, at the car park of a supermarket in Ara Damansara, Petaling Jaya about 6pm.

The man's 31-year-old sister was picked up at a house in Alor Setar about 7.30am yesterday.

In a follow-up operation, the police seized two Glock pistols, two magazines and two boxes of ammunition near the Kuala Kuar beach.

Last Friday, the 43-year-old bomoh from Kedah was riding a motorcycle when he was shot dead at close range about 9pm, by a gunman in a car. At the time, the victim was returning to a relative's apartment in Section 8.

Selangor CID chief SAC Mohd Adnan Abdullah said the motive of the killing was jealousy and revenge.