thai princess
A Thai official dressed in a traditional costume, greets Thailand's Crown Prince Maha Vajiralongkorn (L) and Royal Consort Princess Srirasmi during an annual royal ploughing ceremony in Bangkok May 13, 2013.Reuters

The parents of a former Thai princess were jailed for 2-1/2 years on Wednesday for defaming the monarchy following investigations into the actions of several family members accused of corruption and misusing their royal connection.

Srirasmi Suwadee, formerly known as Princess Srirasmi, is divorced from Crown Prince Maha Vajiralongkorn.

Her parents, Apiruj and Wanthanee Suwadee, were found guilty of violating Article 112 of Thailand's criminal code which says anyone who "defames, insults or threatens the king, the queen, the heir-apparent or the regent" will be punished with up to 15 years in prison.

"Both accused are guilty of royal defamation and are sentenced to 5 years in prison reduced to 2 years and six months," a judge said in delivering the verdict.

Last month they confessed to charges including misuse of their royal connection that led to a former neighbor being jailed on a bogus fraud charge 12 years ago.

Last year several of Srirasmi's relatives were arrested in a purge of officials allegedly involved in corruption. Some were also accused of defaming the monarchy.

Srirasmi relinquished her royal title in December following weeks of speculation over her future.

The imprisonment of her relatives comes at a sensitive time in Thailand, including heightened anxiety over the health of the revered but ailing King Bhumibol Adulyadej, 87, and nervousness about what a royal succession might bring.

Thailand's monarchy is protected by some of the world's strictest lese-majeste laws.

Rights groups say lese-majeste prosecutions have spiked since the army seized power in May, as the military burnishes its reputation as the defender of the royal family.