Youth co-ordinator Shasha Ali said forced marriages mostly involved girls under 18.
"Considering the nature of it being under-reported and often revealed after a long period of client engagement, we do feel that what we are seeing is only the tip of the iceberg.
"For instance, through Shakti services in Auckland alone, we have serviced dozens of cases involving those threatened as well as victim-survivors of forced marriage."
Ms Ali said every woman who has accessed Shakti's service knows of three or four other women in their community who are going through or have gone through the same thing.
"It is difficult to define the extent of forced marriage incidents in New Zealand," she said.
Many forced marriages in New Zealand concealed among family members and within communities, Ms Ali said.
National MP Jackie Blue has drafted a private member's bill which she hopes would help provide extra support for young women under pressure to marry.
Dr Blue's bill would make it illegal for anyone under 18 years old to wed without first formalising their consent before a Family Court judge.
"I believe the majority of marriages under 18 are fine and above board, but this would just give an extra level of protection for those who are being forced to do it against their will," she said.
Dr Blue said her bill would not affect ethnic practices, such as arranged marriage.
"This won't affect this at all, an arranged marriage is a traditional practice and right up until the wedding, the bride can say no."
Ms Ali said the bill was a step in the right direction in terms of acknowledging that the problem exists in New Zealand. Shakti wants stronger legislation to ensure people making marriage arrangements are held liable.
They are also advocating for the legal age for marriage to be lifted to a minimum of 18 years.
In December, police, Child, Youth and Family and the Ministries of Social Development, Education and Immigration signed a letter of agreement outlining their co-ordinated response to victims of the practice.
The parties agreed to work together to help those people faced with forced marriage.
Refugee Council of New Zealand spokesman Gary Poole said that while the steps were positive, he wanted documented evidence of how often forced marriages took place.
"No cases have come to our attention, but that doesn't mean they don't exist. We're somewhat sceptical about the issue (being) beaten up and blown out of proportion."
One woman's story: 'I was so scared for my life'
'Jane* was forced to marry a man she didn't know by her father when she was 17. She had been living in New Zealand for almost 11 years. The Herald has agreed to use a fake name and to not reveal where she is from to protect her privacy and her safety.
"My father told me I would have to return to my homeland because he had chosen a husband for me. I was saying, 'No, no, I don't want this person, I'm still at school, I have to finish my school first'. But my father wasn't happy and he had already sent my mother before me so it would be easier to take me.
"The engagement happened between him (my future husband) and my father through the phone. And then I got home from school and he told me, 'Congratulations, you're getting married' and I was so shocked and I started crying.
"My father bought me a ticket and I started crying but that was all I could do. Then one day he took me to my country for the wedding and ceremony - the plan was to get married soon after, like the next day. So I did. I went with my dad. I felt really lonely and really depressed. No one was there to listen. Everyone knew it was a forced marriage, that I wasn't happy and that I didn't want this to happen, but everyone stayed quiet.
"So they did the marriage and the first time I saw my husband was on my wedding day. I almost lost hope for the future and that I would ever be happy again. There was no point of doing anything anymore. And also my uncle got shot, so it was a very hard time.
"My parents came back to New Zealand and I stayed with my husband for three months. I suffered through all the abuse and he was taking advantage of me. And then I tried to come back but they didn't let me.
"After a few months I managed to get him to trust me and so I came back to New Zealand. Everyone was getting the papers ready so he could come join me and all I had to do was sign it - I didn't give my permission for anything.
"So I contacted Immigration (and said) I didn't want this person (her husband) to come to New Zealand and I was really scared, scared for my life.
A couple of years ago my father apologised, but I don't know if it was from his heart."
Jane* is now 25. She wants to stop the same thing happening to other girls in New Zealand.
Youths married in NZ
by country of origin, 2002-2011
New Zealand
Brides 410
Grooms 97
Overseas
Brides 388
Grooms 77
Brides total 798
Grooms total 174
