Updated at 4.56pm: A barrister and a solicitor were jailed on Wednesday for three years after they were found guilty of blackmailing property tycoon Nina Wang Kung Yu-sum. Judge John Saunders at the District Court rejected the defence of barrister Thomson Mo Sze-lung, 36, and solicitor Ailey Yeung Chin-tat, 30, that the blackmail plot was just a prank. The judge said Mo knew what he had done was wrong although he was suffering a mental condition - a mood disorder - at the time of the offence. Yeung was equally responsible for the offence as the plan would not have got off the ground had he not been in breach of his duties by producing a copy of a confidential document purported to be a will of missing tycoon Teddy Wang Teh-huei, used by Ms Wang, the chairwoman of the Chinachem Group, in a probate action, the judge ruled. The duo were convicted of blackmail. The two alternative charges they denied - namely conspiracy to defraud and attempting to obtain property by deception - were left on court file. The court had heard that the pair tried to extort $10 million from Ms Wang by telling her a favourable forensic report on the will could be secured for that amount of money.