Police on Sunday said they had arrested five people in connection with suspected job scams which allegedly involve Hongkongers being trafficked to Southeast Asia, held captive, and forced to take part in fraudulent activities.

Officers said the number of alleged victims they were trying to help had risen to 36, including some still being held prisoner.

At a press briefing, the force said three men and two women aged between 17 and 51 had been arrested in Hong Kong.

They were suspected of posting fake job adverts online and contacting victims to arrange for them to travel abroad.

Police said the cases they were investigating included 22 Hongkongers still being held against their will in Cambodia and Myanmar. Officers had managed to make contact with 13 of them.

Fourteen other suspected victims were out of the clutches of the trafficking gangs, police said, with 11 of them already back in Hong Kong.

A senior superintendent with the force's organised crime and triad bureau, Ho Chun-tung, said their investigation was not easy.

“Because the whole scam operation is located overseas, there are certain difficulties for us to gather information and also to gather evidence to prosecute, or even to identify those suspects. But we are using all platforms including Interpol to help us to know more, to gather more information and evidence against this deception operation,” he said.

Meanwhile, the DAB said a family has sought help from the party because a relative has been held captive for about a month in Myanmar.

DAB lawmaker Holden Chow said the man told his family he has been physically abused.

"The victim is being detained right now, and every day they could actually call their families, but on a very limited basis. Their call could only last for a few minutes," Chow said.

"He's forced to do some work on a continual basis. The work could last for more than 12 to 13 hours. And if he fails to do his work properly, he will be beaten."

The DAB said it had notified the Foreign Ministry about the man's reported situation.