Former North Korean foreign minister Ri Yong-ho appears to have been executed last year. 

Citing multiple sources familiar with North Korean affairs, the Yomiuri Shimbun reported on Wednesday that Ri was executed sometime between last summer and fall.

The report said that four or five officials from the North Korean foreign ministry appear to have been executed successively around the time of Ri's execution.

It added that the reason for the executions is uncertain, but multiple figures, including Ri, had worked in the North Korean Embassy in Britain. 

The newspaper added that some issues related to the embassy might have been the reasons behind their executions. 

According to Yomiuri, some of the diplomats who were close to the executed officials are expressing fears over the possibility of suffering the same fate.