Tourists extorted by police will be safe from prosecution even though they paid a bribe, including holidaying Taiwanese actress Charlene An, a senior Bangkok police officer said on Wednesday.

The commander of Metropolitan Police Division 1 said interrogators would question witnesses in the case involving Ms An in Singapore and Taiwan to ensure their safety.

The tourists involved in the case would not be prosecuted for bribing police, and would be treated as witnesses because they were seen as the damaged party and were coerced by policemen, he said.

He said 14 policemen set up vehicle checkpoints on Ratchadaphisek Road in front of the Chinese embassy in the early morning of Jan 4, and the group including Taiwanese actress Charlene An was stopped for a search.

She later said she was forced to pay a bribe of 27,000 baht before they let her go.

The commander said seven policemen were at the checkpoint where Ms An's taxi was stopped. These officers had initially been charged with dereliction of duty for failing to prosecute the actress, who allegedly had a vape in her bag.

If the questioning of the witnesses provides enough evidence, police could additionally press extortion charges against the officers.