Three people have been arrested and three children taken into police custody after a raid on a suspected drug-dealing syndicate in Manawatu yesterday.

Twenty police officers, including the armed offenders squad, raided a house in Ferndale Place, Feilding, about 5pm following tip-offs from the public.

A 26-year-old Northland man, 23-year-old Hamilton woman and a 45-year-old Feilding man were arrested.

More than $40,000 in cash and methamphetamine was seized.

Feilding Sergeant Phil Gillbanks said a large container of white power was also found but it was not clear if it was methamphetamine.

"What is particularly concerning is that three children of school and pre-school age were also at the address," he said.

"There are increasing reports in New Zealand of children living lives exposed to toxic chemicals; this type of activity is destroying lives."

Mr Gillbanks said he hoped the raid had put a "significant dent" in the distribution of methamphetamine across Manawatu.

The three people arrested would be interviewed today before a decision was made regarding charges, he said.