Tonga police say there have not been any fraudulently issued passports since it began a crackdown in August last year.
The Commissioner Steve Caldwell was commenting after four people convicted on passport forgery related offences were given jail terms yesterday.
The four are 'Isileli Kaumavae, Sione Sosefo 'Ahohako, Sione Kivalu Heleta and Ola Tameifuna.
Mr Caldwell said the sentencing sent a very clear message about the seriousness of the offending and serves as a deterrent to people tempted to commit such crimes.
In August last year Tonga Police set up a Passport Taskforce headed by Deputy Commissioner Viliami 'Unga and staffed with 16 police investigators.
Since the Taskforce began operations 19 arrests for various passport offences have been made, including the arrests of 6 Georgian nationals who have since been deported from Tonga.
Mr Caldwell said the Taskforce is continuing its work and more arrests are expected in the near future.