The US has called for the immediate release of the jailed activists and criticized the harsh treatment by Nepal's government towards protesting Tibetans.The three Tibetan leaders - Ngawang Sangmo, Tashi Dolma and Kelsang Chung - were taken from their homes on June 19 and told they would be held in preventative detention
for 90 days.
Two of the detained Tibetan leaders have Nepali citizenship, and one is a refugee.
The detentions came on the same day police temporarily detained around 500 Tibetans protesting outside the Chinese Consulate, releasing them several hours later.
The Free Tibet protests have become an almost daily occurrence and the Chinese Ambassador in Kathmandu has called on Nepal to crack down firmly on the dissent.
Govindra Sharma is the lawyer for the three detained leaders.
He said the detentions do not comply with national laws and represent a legal attack on the Tibetan community, after the excessive use of force against monks and nuns was
criticized by the UN and other international organizations.
"I think this is a test case, the government wants to test whether the law they applied would provide them ground to detain other people. So if the Supreme Court upholds the
decision made by the Chief District Officer there will be a lot of preventative detention, because they failed using excessive use of force."
Sharma has lodged a habeas corpus request at the Supreme Court, meaning the authorities must explain why they detained the activists or else release them, but says
the court has been unusually slow to act.
The lawyer has been denied access to the detainees and is concerned they may be mistreated, but others in the Tibetan community who have visited them say they are ingood health.
Meanwhile, a group of 40 Tibetan monks and nuns are walking from Kathmandu towards the northern border with Chinese-controlled Tibet.
They say they will attempt to enter Tibet at a heavily guarded border checkpoint in about two days.