Workers on a North Korean building site have reportedly been given drugs in order to speed up the completion of a huge project.

In an effort to complete the construction of a 70-story high-rise apartment building and around 60 other structures on Pyongyang’s Ryomyung Street, project managers have resorted to extreme measures. 

Speaking to Radio Free Asia (RFA), a source in north Korea state the workers are being given a drug known as 'ice', or crystal meth, as a stimulant.

The project has reportedly required "hundreds of thousands" of workers, and with cold weather likely to slow construction further, supervisors are "openly supplying their exhausted work force with powerful methamphetamines."

The agency claims that, as a result of the harsh conditions and the issuing of the stimulants, graffiti has appeared on the construction sites declaring "Pyongyang speed is drug speed."

Another anonymous source told RFA that the graffiti was reported to the police, which made the matter more serious than it needed to be. 

"There is already a lot of graffiti with obscene content at construction sites or in public restrooms," said the source, "and even if this graffiti was political in its tone, the best way to handle the incident would have been to cover it over and move on."

The construction projects are part of an effort form North Korean leader Kim Jong Un to show that the country is flourishing, despite sanctions and international pressure over the country's nuclear weapons program.

When finished, it will transform the skyline of Pyongyang, with the country's largest building reaching to 70 storeys, another sky scraper that will hit the 50 storey mark, and several other edifices that will reach to between 30 and 40 storeys. 

After the graffiti appeared, the source stated that "investigators are warning construction workers that they will be severely punished for further incidents of this kind" and that they "are undergoing terrible sufferings in their work."

Via Radio Free Asia