North Korean men have reportedly lost yet another freedom of expression: the right to a decent haircut.

According to Radio Free Asia, the regime in Pyongyang is now forcing male university students to cut their hair in imitation of their leader, Kim Jong-un.

Visits to the salon have been tightly controlled for some time in the secretive communist nation, with 10 state-sanctioned hairstyles for men and 18 for women.

Several years ago the North Korean government launched a patriotic campaign against the evils of long hair entitled "Let us trim our hair in accordance with the socialist lifestyle".

But historically, the rules have not been strictly enforced.

With its shaved sides, long top and centre-part, Kim Jong-un's distinctive hair-do is more military in style than that of his late father, Kim Jong-il, who sported more bouffant locks - a style the former leader is rumoured to have adopted in an effort to make himself look taller.

However, recent visitors to the isolated state have cast doubts on the rumour of the 'People's Democratic Trim', saying they noticed no difference in the hairstyles sported by the locals.

Radio Free Asia spoke to one North Korean now living abroad who says the style was never popular in the hermit kingdom before Kim Jong-un's rise to power.

He said it used to be called the "Chinese smuggler haircut" and would attract instant attention from authorities.

Imitation might be the sincerest form of flattery, but the move to make the quiff compulsory for male students is, if true, at odds with other of Kim's policies.

Earlier this year he decreed that North Korean women would be allowed to wear trousers, platform shoes and even earrings.