More than 10 Mtwapa officers were linked to a drug syndicate after several suspects were found with substances including heroin.
Police officers at Mtwapa police station said the ring is believed to fund acts of terror and other crimes in the region.
A source in the department, who sought anonymity, said police found messages that showed the implicated officers had been communicating with suspects.
The source said some of the messages were of M-Pesa transactions.
"It is a big syndicate. Some officers have gone on leave to avoid infamy. We have good sources... We are targeting the main drug lords," the source said.
Among the suspects arrested on Wednesday night were Rajab Mohamed alias Burning and Ezekiel Waithaka.
They were arrested within Mtomondoni with 17g and 297 sachets of heroin, whose street value is Sh200,000.
Coast regional coordinator Nelson Marwa said a major crackdown will follow and that no one will be spared.
Marwa said measures have been taken, including the deployment of a special border control unit.
He declined to comment on the reports implicating officers saying the matter was under investigation.
Detectives also launched a probe into allegations that smuggled firearms are stored at a factory in Kilifi county.
A source at the factory decried slow action by authorities despite the receipt of reports.
"We are worried since
police officers were informed but nothing has been done. We assume they might have been compromised," he said.
Kilifi police said investigations were underway.