Defections unlikely

Now living in South Korea after defecting in 2006, Han Seo-hee was chosen in her twenties to be part of a North Korean cheerleading troupe after she performed for late leader Kim Jong Il.

She says it's unlikely that cheerleaders would defect during such a high-profile visit.

The team would be monitored everywhere they go and would be keenly aware of the consequences their family back home would face were they to make such a move, Han says.

"I wouldn't have even considered it." Han says. "It will be the same for the cheerleading squad this time. They have family back home, they know if they defect, their family will be terrified and punished."

"A North Korean group sent abroad is always composed of three parties. Party members, security members and administrative members. This time will be the same."

No time alone

The relentless glare of public scrutiny would be intense -- even intimidating -- for any athlete competing in the Games, which officially begin Friday.

A former North Korean police officer, who didn't want to be identified because he still has family in the North, told CNN scrutiny would continue for the North Korean athletes out of the public eye.

He said team members would be under 24-7 surveillance -- unable to go to the bathroom alone and informants would monitor who is talking to whom.

Han said the very nature of North Korean life means everyone is encouraged to look for unusual or suspicious behavior in friends or family and report it.

"Not only the leaders but also the rest of the performers will be punished for not reporting suspicious signs of a defector."

Intensive training

The North Koreans already in Pyeongchang have been chased by media everywhere they go.

In most cases, they give disciplined smiles and little response to the barrage of questions -- although at Thursday's welcoming ceremony for North Koreans at the Gangneung athletes village some of the delegation were visibly relaxing as the ceremony progressed, even giving the Olympic mascot Soohorang high fives.

Han said she was told not to talk if she went abroad, to ignore journalists' questions and not to make eye contact.

"We were educated that we would be sent to South Korea not only to cheerlead but also to boast about our leader. We were told that we should take the fight to the heart of our enemies."

Isolated?

The North Korean athletes have taken three floors of accommodation in the Gangneung Olympics village. Each apartment has two or more beds — the North Koreans would not be staying in rooms alone, according to the former police officer.

The athletes have made their presence known by hanging from a window a massive North Korean flag that covers all three floors. Such a move that could land you in jail on a normal day, but these Olympic Games are not normal and the flag is allowed by the International Olympic Committee.

The performing art troupe has been staying aboard the Man Gyong Bong ferry which brought them to the South this week -- an easy way to protect the North Korean orchestra from both protestors and temptation.

But Han says those within the troupe would be from a 'good background' and loyal to the regime so thoughts of defection would be unlikely.

Scrutiny continues back home

Lee Chul-sung, the head of South Korean police in charge of security for the Games, says North Korea was not allowed to bring its own official security and he has organized a separate field team to accompany North Korean delegations wherever they go.

"I wouldn't go so far as to say the athletes are isolated, but they are separated from the other athletes. We will have extra security for them."

Lee says there are also South Korean guards permanently outside their living quarters to keep the delegations secure. Small protests have erupted wherever they go, with some in South Korea angry the door has been opened to North Korea without the country having to make any concessions on its nuclear missile program.

The North Korean ex-police officer told CNN the surveillance surrounding the North Korea team, performers and officials would be covert and the intelligence officers would have titles like support staff.

The scrutiny and surveillance also wouldn't ease up once they were back home, he says.

The athletes, performers and cheerleaders would be subject to reviews, debriefs, and investigations to find out how each person represented their country to the outside world.