Paljor Norbu, who is in his eighties, was sentenced to seven years in prison for printing illegal materials - including the banned national Tibetan flag - which are said to have been produced for the 2008 spring protests.
It was claimed that correct legal procedures were not followed during Paljor's trial and he was not allowed defence representation in court.
Out of business
Paljor's family printing business in Barkhor, which employed dozens of workers, had produced various cultural and religious materials and Buddhist texts for monasteries.
Following his arrest, the printing blocks were confiscated and the shop was closed - a sign was placed on the door telling workers not to return.
The judicial authorities did not inform Paljor's family about his whereabouts - which remain unknown - and his age makes relatives even more worried.
A source said that "The family wants to know what prison he is in because it is getting cold, he is very old, and they want to get warm clothes and blankets to him."