An employee of King County’s Marine Division was arrested May 28 for theft of $7,500 in water taxi cash fares over the past two months.

The 30-year-old Tacoma man, who had been working for the Marine Division since April, was arrested and released, according to a press release issued by the King County Sheriff’s Office. But officials believe he will be charged with felony theft after an investigation into the thefts is completed.

King County Sheriff’s detectives began an investigation on May 27, after officials at the county Marine Division — which operates two water taxis, one between Vashon and downtown Seattle and the other between West Seattle and downtown Seattle — noticed that money seemed to be disappearing from a safe at Pier 50 in Seattle, where both county water taxis land.

Detectives believed the thefts were done by someone within the department, and soon honed in on a particular employee as a person of interest. After further investigation, a search warrant was obtained for the employee’s home, and a search there turned up seven of the small “vaults” where taxi riders deposit cash.

Fares from passengers are deposited in the vaults, then stored in a larger safe until they are picked up by an armored car and taken to a bank. Apparently, the employee had access to the larger safe, and stole 26 vaults during the past two months. Each vault itself is worth about $330, and the 26 vaults contained a total of about $7,500 in cash. The man gained access to the money in the vaults by smashing them with a hammer, according to the press release.