The arrest has been made by the Anti-Corruption Unit in the Colombo North Division at the Modara area in Colombo.
A total of 1 kilogram and 21 grams of heroin has been found in the possession of the woman.
The stash of heroin recovered from the suspect is estimated to be nearly Rs 10 million, the Police said.
Reportedly, the arrested female is 25-year-old.
Police intend to obtain a 7-day detention order on the suspect after producing her before a court, the police spokesman said.