Human rights group Amnesty International has voiced serious concern over the prolonged detention of Indian doctor Mohammed Haneef, who has been held without charge for more than a week by Australian police in connection with their probe into the foiled UK terror plot.

"The whole case against Haneef undermines the presumption of innocence," Australia-based Amnesty spokeswoman Nicole Bieske said.

"This situation has become far worse than we originally feared when the legislation (Australian anti-terror laws) was introduced," Nicole said.

"Compounding the problem is that it is very hard for his (Haneef) lawyer to properly represent Haneef, when he doesn't have full access to the information about his client's case," she was quoted as saying by The Australian newspaper.

Amnesty said Canberra's anti-terror powers place no cap on the length of time a person could be held in custody.

"The whole situation flies in the face of the rule of law. If his case goes to trial the presumption of innocence has already been significantly affected. If he is released he (Haneef) will not be able to return to normal life without suspicion," the rights group said.

Haneef has been held in the Brisbane watch house since July 2.