Three asylum seekers had to be rescued on the weekend after a failed attempt to escape from the Manus Island detention centre in Papua New Guinea.

Immigration Department spokesman Sandi Logan said three men climbed the detention centre fence on Saturday night and ended up in the water.

Mr Logan said the men were rescued and one was treated at the health clinic.

According to an official department statement, the group tried to escape but did not succeed.

They were among 40 men from Iran, Iraq and Afghanistan who were moved from Australia to the detention centre on Saturday.