離職後想重新投考政府部門須唔須要再body check ?

You need to have body check in this case. However, if you are applying for internal transfer (for example, from Immigration to Police, without service break), they can waive your body check. But it really depends on whether the body check are the same.

For example, if you are a clerk, then you may need to have body check if you transfer to Police as their requirement are totally different.

凡入職都要body check,無論你之前有冇做過政府.