Thailand’s judiciary on Thursday dealt a significant blow to the family of Thaksin Shinawatra, the former prime minister and business tycoon, by sentencing his wife and her brother to three years in jail for tax evasion.

The verdict was the first in a string of cases involving Mr Thaksin, members of his family and close associates. It follows two months of mass street protests against a coalition government elected in December on a pro-Thaksin ticket and that opponents accuse of continuing to promote his business dealings.