A city employee who allegedly pocketed more than $100,000 over 10 years by falsifying motor vehicle registrations in exchange for cash also is awaiting trial on charges of possessing crystal methamphetamine and marijuana, according to court documents and city officials.

Brian K. Hamasaki, 50, was arrested Monday on suspicion of bribery, a Class C felony. He was released pending investigation. If convicted, he faces up to five years in prison and a $10,000 fine.

The city placed Hamasaki on administrative leave on April 26 and turned over the results of an internal investigation to police, the city said. Hamasaki was put on leave after officials detected "possible improprieties" in some vehicle registration transactions. City officials became suspicious of Hamasaki after he was caught on surveillance video doing work well before he was set to start his shift.

Hamasaki has worked for the city for the past 15 years as a customer service representative for the city's motor vehicle licensing division on Fort Street Mall. Hamasaki earned between $2,500 and $3,200 a month, according to city officials.

"We won't tolerate criminal behavior by city workers," said Bill Brennan, press secretary for Mayor Mufi Hannemann. "As soon as we found out something might be going on we acted on it and did not let it linger."

The city is continuing an internal investigation into Hamasaki's actions and officials are sharing information with police, Brennan said.

According to a police affidavit filed in O'ahu Circuit Court, Hamasaki "fraudulently updated City and County of Honolulu motor vehicle registrations for a cooperating individual for a period in excess of ten years."

According to the affidavit, the "cooperating individual" told police that Hamasaki offered to update vehicle registrations for trucks and trailers in exchange for 50 percent of the actual registration fee for two years.

After the two-year period, Hamasaki began charging 70 percent of the actual registration fee, according to court documents.

Hamasaki also updated commercial and private motor vehicle registrations for family members of the person cooperating with the investigation.

Michelle Yu, public information officer for the Police Department, declined to discuss the amount of revenue lost by the city. She said an investigation is ongoing but would not say whether any other individuals may have been helping Hamasaki.

"These things always take time," she said.

In December, Hamasaki was arrested at Honolulu International Airport after a security search yielded a small amount of marijuana and two glass pipes, one of which was packed with crystal methamphetamine, according to city prosecutors.

Hamasaki was scheduled to stand trial Tuesday on charges of promoting a dangerous drug in the third-degree, possession of drug paraphernalia, and promotion of a detrimental drug in the third-degree. That case was continued following his arrest Monday.

Reach Peter Boylan at pboylan@honoluluadvertiser.com.