By Jun Ji-hye

Former North Korean diplomat Thae Yong-ho defected to South Korea due to pressure from the Kim Jong-un regime to bribe British officers in order to obtain the country's nuclear deterrent secrets, according to a British newspaper, Sunday.

Thae, who was deputy ambassador at the North Korean Embassy in the U.K., fled to Seoul in August with his wife and children, becoming one of the highest-ranking North Korean officials to escape the repressive state.

The Sunday Express reported that before Thae's defection, Pyongyang was looking to bribe a U.K. Ministry of Defense civil servant or naval officer with 1 million pounds ($1.2 million) to obtain British nuclear secrets.

Thae revealed the plot during an interview with South Korean, American and British intelligence officers, saying that the pressure to carry out the "impossible" order was a major factor in his decision to defect.

According to the newspaper, Thae received the order two years ago when the North was working to develop its submarine launched ballistic missile (SLBM) technology. The isolated state has successfully launched the SLBM this year, but its submarine program requires more development.

The diplomat said that he informed Pyongyang that the odds of enticing any British civil servant of the Royal Navy Submarine Service were so remote as to be "impossible," according to the paper. But the Kim regime told Thae that if he failed in the mission, it would end his diplomatic career, the newspaper added.

When disclosing Thae's defection in August, an official from Seoul's Ministry of Unification said one of the major causes for his defection was presumed to be the education of his children.