The family of a Sri Lankan man living in Australia says terrorism charges against him have been dropped.

Kamer Nizamdeen, a 25-year-old working at the University of New South Wales, had been under investigation for terrorism since he was arrested by Australian authorities in August. Police said they found in his notebook plans to carry out terrorist acts in Sydney.

Nizamdeen's family, which maintains that the handwriting in the notebook isn't his, said the charges were dropped on Friday.

Nizamdeen was kept in solitary confinement for weeks before he was released on bail late last month.

His family, friends and activists held protests in Colombo, Sri Lanka's capital, urging Australian authorities to speed up the investigation, claiming Nizamdeen could have been framed.

Nizamdeen's attorney Moustafa Kheir said his client would seek legal costs and other compensation from Australian police.

"What the authorities have done to this young man is absolutely unforgivable," he told reporters outside the court. "It's a terrible experience, the young man has done everything right in life."