Four electricians from the United States and Britain who came to Japan to work on the Tokyo Olympics have been arrested on suspicion of using cocaine, police said Tuesday.

The four -- two Britons and two Americans -- were arrested between July 3 and 5, but have denied the allegations, according to the police.

The four had entered Japan between February and May to take part in maintenance work for electric generators used at venues for the Tokyo Games, commencing their duties after completing a 14-day quarantine.

On July 2, all four were drinking at a bar in the capital's central Roppongi district from around 8 p.m. After leaving the bar, one of the suspects trespassed at a nearby apartment, prompting the police to hurry to the scene, according to the police.

A drugs test on the four men revealed cocaine use, they said.

Olympic minister Tamayo Marukawa said at a press conference Tuesday, "If (their crime) proves to be true, it's an incident that could damage the image of the games. It's really unfortunate."

The four, who are suspected of using cocaine between July 3 and 4, are employees of Tokyo-based Aggreko Events Services Japan, a local subsidiary of a foreign-owned firm dealing with electric generators.

The company said it is fully cooperating with the police investigation and that the four men have been suspended from their posts.

"We deeply apologize for any inconvenience this incident may have caused to the people of Japan, the Tokyo Organizing Committee of the Olympic and Paralympic Games, the athletes, and the many people who are working to ensure the safety of the Tokyo Olympics," it said in a statement.

The games organizers said it has issued a warning to Aggreko Events Services Japan and urged it to ensure no such similar incidents occur.

In light of the incident, Marukawa said, "Nonessential outings at night will not be tolerated, even after the quarantine period is over."